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Diplomatic immunity

Diplomatic immunity is a principle of international law by which certain foreign government officials are recognized as having legal immunity from the jurisdiction of another country. It allows diplomats safe passage and freedom of travel in a host country and affords almost total protection from local lawsuits and prosecution.

Diplomatic immunity is one of the oldest and most widespread practices in international relations; most civilizations since antiquity have granted some degree of special status to foreign envoys and messengers. It is designed to facilitate relations between states by allowing their respective representatives to conduct their duties freely and safely, even during periods of political tension and armed conflict. Moreover, such protections are generally understood to be reciprocal and therefore mutually beneficial.

As a longstanding and nearly universal concept, diplomatic immunity has long been considered customary law; however, it was traditionally granted on a bilateral, ad hoc basis, leading to varying and sometimes conflicting standards of protection. Modern practices of diplomatic immunity have largely conformed to the 1961 Vienna Convention on Diplomatic Relations, which formally codified the legal and political status of diplomats, and has been ratified by the vast majority of sovereign states.

Contrary to popular belief, diplomats are not entirely immune from the jurisdiction of their host country. Like most foreign persons, they may still be declared persona non grata and expelled. A foreign official's home country may waive immunity, typically in the event that they are involved in some manner in a serious crime unrelated to their diplomatic role (as opposed to, for example, allegations of spying). However, many countries refuse to waive immunity as a matter of course, and diplomats have no authority to waive their own immunity (except perhaps in cases of defection). Alternatively, the home country may prosecute the individual on its own accord or through the insistence of the host country.

Prior to modern period

The concept of diplomatic immunity can be found in ancient Indian epics like Ramayana and Mahabharata, where messengers and diplomats were given immunity from capital punishment. In Ramayana, when the demon king Ravana ordered the killing of Hanuman, Ravana's younger brother Vibhishana pointed out that messengers or diplomats should not be killed, as per ancient practices.

During the evolution of international justice, many wars were considered rebellions or unlawful by one or more combatant sides. In such cases, the servants of the "criminal" sovereign were often considered accomplices and their persons violated. In other circumstances, harbingers of inconsiderable demands were killed as a declaration of war. Herodotus records that when heralds of the Persian king Xerxes demanded "earth and water" (i.e., symbols of submission) of Greek cities, the Athenians threw them into a pit and the Spartans threw them down a well for the purpose of suggesting they would find both earth and water at the bottom, these often being mentioned by the messenger as a threat of siege. However, even for Herodotus, this maltreatment of envoys is a crime. He recounts a story of divine vengeance befalling Sparta for this deed.

A Roman envoy was urinated on as he was leaving the city of Tarentum. The oath of the envoy, "This stain will be washed away with blood!", was fulfilled during the Pyrrhic War.

Gregory of Tours recorded that Frankish envoys sent from King Childebert II to the Byzantine emperor Maurice were killed in Carthage by the prefect of the city, after one of the Franks had murdered a merchant. After Emperor Maurice heard about this, he ordered for several Carthaginians to be arrested and sent to Childebert for judgment on account of what happened to his envoys.

The arrest and ill-treatment of the envoy of Raja Raja Chola by the king of Kulasekhara dynasty (Second Cheras), which is now part of modern India, led to the naval Kandalur War in AD 994.

The Islamic prophet Muhammad sent and received envoys and strictly forbade harming them. This practice was continued by the Rashidun caliphs who exchanged diplomats with the Ethiopians and the Byzantines. This diplomatic exchange continued during the Arab–Byzantine wars.

Classical Sharia called for hospitality to be shown towards anyone who has been granted amān (or right of safe passage). Amān was readily granted to any emissary bearing a letter or another sealed document. The duration of the amān was typically a year. Envoys with this right of passage were given immunity of person and property. They were exempt from taxation, as long as they did not engage in trade.

As diplomats by definition enter the country under safe conduct, violating them is normally viewed as a great breach of honor. Genghis Khan and the Mongols were well known for insisting on the rights of diplomats, and would often take terrifying vengeance against any state that violated these rights; at times razing entire cities in retaliation for the execution of their ambassadors. The Mongols invaded and destroyed the Khwarezmid Empire after their ambassadors were mistreated.

16th–19th century
The British Parliament first guaranteed diplomatic immunity to foreign ambassadors under the Diplomatic Privileges Act in 1709, after Count Andrey Matveyev, a Russian resident in London, was subjected to verbal and physical abuse by British bailiffs.

Modern diplomatic immunity evolved parallel to the development of modern diplomacy. In the 17th century, European diplomats realized that protection from prosecution was essential to doing their jobs, and a set of rules evolved guaranteeing the rights of diplomats. These were still confined to Western Europe and were closely tied to the prerogatives of nobility. Thus, an emissary to the Ottoman Empire could expect to be arrested and imprisoned upon the outbreak of hostilities between his state and the empire. The French Revolution also disrupted this system, as the revolutionary state and Napoleon imprisoned numerous diplomats who were accused of working against France. More recently, the Iran hostage crisis is universally considered a violation of diplomatic immunity. Although the hostage takers did not officially represent the state, host countries are obligated to protect diplomatic property and personnel. On the other hand, during World War II, diplomatic immunity was upheld and the embassies of the belligerents were evacuated through neutral countries.

For the upper class of the 17th, 18th, and 19th centuries, diplomatic immunity was an easy concept to understand. The first embassies were not permanent establishments but actual visits by high-ranking representatives, often close relatives of the sovereign, or by the sovereign in person. As permanent representations evolved, usually on a treaty basis between two powers, they were frequently staffed by relatives of the sovereign or high-ranking nobles.

Warfare was a status of hostilities not between individual states but between their sovereigns, as well as the officers and officials of European governments, and armies often changed employers. Truces and ceasefires were commonplace, as was the fraternization between officers of opposing armies. If officers were taken prisoner, they usually gave their parole and were only restricted to a city away from the theatre of war. Almost always, they were given leave to carry their personal sidearms. Even during the French Revolutionary Wars, British scientists visited the French Academy. In such an atmosphere, it was easy to accept that some persons were immune to the laws. After all, they were still bound by strict requirements of honour and customs.

Modern era and Vienna convention
In the 19th century, the Congress of Vienna reasserted the rights of diplomats; they have been largely respected since then, as the European model has spread throughout the world. Currently, diplomatic relations, including diplomatic immunity, are governed internationally by the 1961 Vienna Convention on Diplomatic Relations, which has been ratified by almost every country in the world.

In modern times, diplomatic immunity continues to provide a means, albeit imperfect, to safeguard diplomatic personnel from any animosity that might arise between nations. As one article put it: "So why do we agree to a system in which we're dependent on a foreign country's whim before we can prosecute a criminal inside our own borders? The practical answer is: because we depend on other countries to honor our own diplomats' immunity just as scrupulously as we honor theirs."

During the 18 April 1961 Vienna Convention, the Holy See was granted diplomatic immunity to its foreign ambassadors as well.

In the United States, the Diplomatic Relations Act of 1978 ( et seq.) follows the principles introduced by the Vienna Conventions. The United States tends to be generous when granting diplomatic immunity to visiting diplomats, because a large number of US diplomats work in host countries less protective of individual rights. If the United States were to punish a visiting diplomat without sufficient grounds, US representatives in other countries could receive harsher treatment. If a person with immunity is alleged to have committed a crime or faces a civil lawsuit, the State Department asks the home country to waive immunity of the alleged offender so that the complaint can be moved to the courts. If immunity is not waived, prosecution cannot be undertaken. However, the State Department still has the right to expel the diplomat. In many such cases, the diplomat's visas are revoked, and they and their family may be barred from returning to the United States. Crimes committed by members of a diplomat's family can also result in dismissal.

Exceptions to the Vienna Convention
Some countries have made reservations to the Vienna Convention on Diplomatic Relations, but they are minor. A number of countries limit the diplomatic immunity of persons who are citizens of the receiving country. As nations keep faith to their treaties with differing zeal, other rules may also apply, though in most cases this summary is a reasonably accurate approximation. The Convention does not cover the personnel of international organizations, whose privileges are decided upon on a case-by-case basis, usually in the treaties founding such organizations.

UN organisations
The United Nations system (including its agencies, which comprise the most recognizable international bodies such as the World Bank and many others) has a relatively standardized form of limited immunities for staff traveling on UN laissez-passer; diplomatic immunity is often granted to the highest-ranking officials of these agencies. Consular officials (that do not have concurrent diplomatic accreditation) formally have a more limited form of immunity, generally limited to their official duties. Diplomatic technical and administrative staff also have more limited immunity under the Vienna Convention; for this reason, some countries may accredit a member of technical or administrative staff as an attaché.

Others
Other categories of government officials that may travel frequently to other countries may not have diplomatic passports or diplomatic immunity, such as members of the military, high-ranking government officials, ministers, and others. For the US military, official passports can be used for work related travels only. Many countries provide non-diplomatic official passports to such personnel, and there may be different classes of such travel documents such as official passports, service passports, and others. De facto recognition of some form of immunity may be conveyed by states accepting officials traveling on such documents, or there may exist bilateral agreements to govern such cases (as in, for example, the case of military personnel conducting or observing exercises on the territory of the receiving country).

Formally, diplomatic immunity may be limited to officials accredited to a host country, or traveling to or from their host country. In practice, many countries may effectively recognize diplomatic immunity for those traveling on diplomatic passports, with admittance to the country constituting acceptance of the diplomatic status. However, this is not universal, and diplomats have been prosecuted and jailed for crimes committed outside the country they are accredited to.

As a result of their title, diplomats are exempt from being prosecuted by the state in open court when they are suspected to be guilty of a crime. Not only are these agents free from the criminal jurisdiction of the state, they are also immune from administrative and civil jurisdiction. This applies for most scenarios; however, there are some exceptions when the diplomatic immunity is subject to waiver.

 * 1) Any events that are associated with individual stationary property in the land of the given receiving State – with the exception of whether or not he is directed to do so for a plan.
 * 2) Any events with regards to a diplomat serving as another role from another State, including heir, inheritor of a will, executor, administrator.
 * 3) Any activity by a diplomat, in the receiving State, that is related to any professional or commercial operations beyond the scope of his directed responsibilities.

Asadollah Asadi, an Iranian diplomat, was arrested while returning to his residence in Austria on a highway in Germany on June 10, 2018, accused of being involved in an attempted bombing at a gathering of the National Council of Resistance of Iran (a political organisation opposing the Iranian regime). While Assadi was entitled to diplomatic immunity where applicable, it was deemed that he was not protected when he was arrested as he was on holiday (in Germany) outside the country where he was posted and hence protected.

Uses and abuses
In reality, most diplomats are representatives of nations with a tradition of professional civil service; they are expected to obey regulations governing their behaviour and suffer severe disciplinary action if they flout local laws. In many nations, a professional diplomat's career may be compromised if they (or members of their family) disobey the local authorities or cause serious embarrassment, and such cases are, at any rate, a violation of the spirit of the Vienna Conventions.

The Vienna Convention is explicit that "without prejudice to their privileges and immunities, it is the duty of all persons enjoying such privileges and immunities to respect the laws and regulations of the receiving State." Nevertheless, on some occasions, protected diplomats have violated laws (including those that would be violations at home as well) of the host country, and that country has been essentially limited to informing the diplomat's nation that the diplomat is no longer welcome (persona non grata). Diplomatic agents are not, however, exempt from the jurisdiction of their home state, and hence prosecution may be undertaken by the sending state. For minor violations of the law, the sending state may impose administrative procedures specific to the foreign service or diplomatic mission.

Violation of the law by diplomats has included espionage, smuggling, child custody law violations, money laundering, tax evasion, making terrorist threats, slavery, child solicitation, and murder.

Offences against the person
On-duty police officer Yvonne Fletcher was murdered in London in 1984, by a person shooting from inside the Libyan embassy during a protest. The incident caused a breakdown in diplomatic relations until Libya admitted "general responsibility" in 1999. The incident became a major factor in Prime Minister Margaret Thatcher's decision to allow President of the United States Ronald Reagan to launch the US bombing of Libya in 1986 from American bases in the United Kingdom.

In 1987, the Human Resources Administration of New York City placed 9-year-old Terrence Karamba in a foster home after his elementary school teachers noticed suspicious scars and injuries. He and his 7-year-old sister, who was also placed in city custody, told officials the wounds had been inflicted by their father, Floyd Karamba, an administrative attaché at the Zimbabwean Mission to the UN. No charges were filed, as Karamba had diplomatic immunity.

In February 1999 in Vancouver, British Columbia, Canada, Kazuko Shimokoji, wife of the Japanese Consul-General, showed up at the emergency department of a city hospital with two black eyes and a bruised neck. She told doctors that her husband had beaten her. When local police questioned her husband, Mr. Shimokoji said, "Yes, I punched her out and she deserved it", and described the incident as "a cultural thing and not a big deal". Although an arrest warrant was issued, Mr. Shimokoji could not be arrested due to his diplomatic immunity. However, his statement to the police was widely reported in both the local and Japanese press. The subsequent public uproar prompted the Japanese Ministry of Foreign Affairs to waive Mr. Shimokoji's immunity. Though he pleaded guilty in Canadian court, he was given an absolute discharge. Nonetheless, he was recalled to Japan where he was reassigned to office duty and had his pay cut.

In 2002, a Colombian diplomat in the United Kingdom was prosecuted for manslaughter once diplomatic immunity was waived by the Colombian government.

In November 2006 in New York City, Fred Matwanga, Kenyan diplomat to the UN, was taken into police custody by officers responding to reports that he had assaulted his son; he was released after asserting diplomatic immunity.

In 2011, Turkish president Erdogan and his team started fighting with UN officials at the United Nations Headquarters. The then secretary general, Ban Ki Moon, soon ran over and apologised to Erdogan.

In April 2012 in the Philippines, Erick Shcks Bairnals, a technical officer of the Panama Maritime Authority's regional office in Manila, was accused of raping a 19-year-old Filipino woman. Being an attached agency to the Panamanian embassy in Manila, the AMP office was classified as a diplomatic entity, its officers possessing the same privileges conferred to the embassy's diplomats. Shcks was later released from detention because Shcks "enjoys protection under the 1961 Vienna Convention."

In March 2013, the Supreme Court of India restricted Italian ambassador Daniele Mancini from leaving India for breaching an undertaking given to the apex court. Despite Italian and European Union protests regarding the restrictions as contrary to the Vienna Convention on Diplomatic Relations, the Supreme Court of India said it would be unacceptable to argue diplomatic immunity after voluntarily submitting to the court's jurisdiction. The Italian envoy had invoked Article 32 of the Constitution of India when filing an affidavit to the Supreme Court taking responsibility for the return of the two Italian marines to India after casting their votes in the March 2012 general elections in Italy. The Indian Supreme Court opined that the Italian ambassador had waived his diplomatic immunity and could be charged for contempt. The two marines were being tried in India for the murder of two Indian fishermen off the coast of Kerala (see the Enrica Lexie case).

In October 2013, Russian diplomat Dmitri Borodin was arrested in The Hague, The Netherlands, after neighbours called the police. Borodin was alleged to have been drunk and violent towards his children, aged two and four. Police were in the area because Borodin's wife had lost control over her car while also intoxicated, and had rammed four parked cars near the diplomats' house. Russia immediately demanded an apology from the Dutch government for violating Borodin's diplomatic immunity. The row came at a time of tension between Russia and the Netherlands, after the Russian security services captured a Greenpeace vessel sailing under the Dutch flag, Arctic Sunrise, that was protesting against oil drilling in the Prirazlomnoye field.

In June 2014, the New Zealand government confirmed that Mohammed Rizalman Bin Ismail from Malaysia, aged in his 30s and employed at Malaysia's High Commission in Wellington, had invoked diplomatic immunity when faced with charges of burglary and assault with intent to rape after allegedly following a 21-year-old woman to her home. He returned to Malaysia in May 2014 with his family while the case was still in hearing. The New Zealand foreign ministry was criticized for allowing the defendant to leave the country, which was blamed on miscommunication between the foreign ministries of the two countries, as Prime Minister John Key expressed his view that "the man should have faced the charges in New Zealand". Malaysia eventually agreed to send the diplomat back to assist in investigations and he was eventually tried and sentenced to nine months' home detention in New Zealand.

In July 2017, in Jordan, two Jordanian carpenters were invited to repair furniture at an Israeli diplomatic security agent's residence near the Israeli embassy. It is believed that the Jordanians and Israeli security agent quarreled over the ongoing tensions regarding the installations of metal detectors at entry points to al-Aqsa mosque in Jerusalem. One carpenter, a teenager of Palestinian origin reportedly tried to stab the Israeli security agent with his screwdriver, and the Israeli security agent shot and killed the Jordanian carpenter, and also shot the property landlord as well, a doctor, who happened to be there at the time. Israel refused to allow Jordanian authorities to question the agent, claiming diplomatic immunity under the Vienna convention.

In August 2017, Grace Mugabe, the former First Lady of Zimbabwe, invoked diplomatic immunity on 15 August after assault charges were laid against her by a South African model.

In 2018, Saudi American journalist Jamal Khashoggi was killed by Saudi officials inside the Saudi embassy in Turkey. The Turkish police were not allowed to enter the premises days after this death. Furthermore, a Saudi government vehicle with diplomatic license plates was spotted entering a park.

In August 2022, UN diplomat Charles Dickens Imene Oliha of South Sudan's Ministry of Foreign Affairs claimed diplomatic immunity and was released from jail in New York City after raping a woman twice inside her apartment building. He subsequently returned to South Sudan, where he was suspended from his duties and is to be investigated.

Theft
In April 2021, two Pakistani diplomats in South Korea were caught shoplifting in Seoul. The Pakistani diplomats were caught stealing $1.70 chocolate and a $10 hat. The case was closed owing to their diplomatic immunity.

Smuggling
Diplomats and officials involved in drug smuggling have benefited from diplomatic immunity. For example, a Venezuelan general wanted in the United States on drugs charges was arrested in Aruba only to be released after the Venezuelan government protested his diplomatic immunity and threatened sanctions if Aruba did not release him.

In December 2014, Gambian diplomats were found guilty by Southwark Crown Court of London for selling tax-free tobacco from the Gambian embassy in the United Kingdom. The Crown Prosecution Service told the court that much of this was sold from the embassy without paying value-added tax and excise duty.

Employer abuse and slavery
Diplomatic immunity from local employment and labor law has precipitated incidents in which diplomatic staff have been accused of abusing local workers, who are often hired for positions requiring local knowledge (such as an administrative assistant, press/PR officer) or for general labor. In such situations, the employees are in a legal limbo where the laws of neither the host country nor the diplomat's country are enforceable. Diplomats have ignored local laws concerning minimum wages, maximum working hours, vacation and holidays, and in some cases have imprisoned employees in their homes, deprived them of their earned wages, passports, food, and communication with the outside world, abused them physically and emotionally, and invaded their privacy. Reported incidents include the following:

 * In 1999, a Bangladeshi woman, Shamela Begum, claimed she had been enslaved by a senior Bahraini envoy to the United Nations and his wife. Begum charged that the couple took her passport, struck her, and paid her just $800 for ten months of service—during which she was only twice allowed out of the couple's New York apartment. The envoy and his wife claimed diplomatic immunity, and Begum later reached a civil settlement with her employers. By some estimates, "hundreds of women have been exploited by their diplomat employers over the past 20 years."
 * In 2003 in Finland, a Filipina maid escaped from an embassy of an unidentified Asian country, and reported being held in conditions approaching slavery: she was forced to work from 7 a.m. to 10 p.m., 7 days a week, and the ambassador's children were permitted to hit her. On grounds of diplomatic immunity, no charges could be filed.
 * In 2009, South Africa was criticised for claiming immunity from labor laws relating to a Ukrainian domestic worker at the residence of the South African ambassador in Ireland.
 * In 2010, the American Civil Liberties Union filed an amicus brief in Swarna v. Al-Awadi to argue that human trafficking is a commercial activity engaged in for personal profit, which falls outside the scope of a diplomat's official functions, and therefore diplomatic immunity does not apply. An appeals court ruled that Al-Awadi did not have diplomatic immunity in that situation.
 * In 2013, Indian consular official Devyani Khobragade was detained, hand-cuffed, strip searched, DNA swabbed, and held in a federal holding cell in New York, relating to allegations of non-payment of US minimum wage and for fraudulently lying about the wages to be paid on a visa application for her domestic worker. India registered a strong protest and initiated a review of privileges afforded to American consular officials in India as a result.
 * In 2015, two Nepalese women were rescued from the fifth floor of the Gurgaon residence of a Saudi Arabian diplomat in India. They were allegedly confined there and abused physically and sexually by the diplomat and his family and friends. The women were rescued in a police raid planned after the police received a letter from the Nepal embassy regarding their plight. Several persons, the Saudi diplomat among them, were booked for wrongful confinement and gang rape. Saudi Ambassador Saud Mohammed Alsati commented, "This is completely false. We would not like to comment any further since the case is under investigation by the Indian police." Ten days after the diplomat was accused, it was confirmed that he had left India.

Parking violations
A particular problem is the difficulty in enforcing ordinary laws, such as prohibitions on double parking. For example, the Autobahn 555 in Cologne, Germany was nicknamed the "Diplomatenrennbahn" (Diplomat's Raceway), when Bonn was the capital of West Germany, because of the numerous diplomats that used to speed through the highway under diplomatic immunity. Certain cities, for example The Hague and New York City have taken to impounding such cars rather than fining their owners. Diplomats' status does not guarantee the release of impounded cars. Diplomats' cars may not be searched or entered in the US.

Diplomatic missions have their own regulations, but many require their staff to pay any fines due for parking violations. A 2006 economic study found that there was a significant correlation between home-country corruption (as measured by Transparency International) and unpaid parking fines: six countries had in excess of 100 violations per diplomat: Kuwait, Egypt, Chad, Sudan, Bulgaria and Mozambique. In particular, New York City, which hosts the United Nations Headquarters, regularly protests to the United States Department of State about nonpayment of parking tickets because of diplomatic status. In 2001, the city had more than 200,000 outstanding parking tickets from diplomats, totaling more than $21.3 million, of which only $160,682 had been collected; a decade later, the total cost of unpaid parking tickets was over $17 million. In 1997, then-mayor Rudy Giuliani proposed to the Clinton administration that the U.S. State Department revoke the special DPL plates for diplomats who ignore parking summonses; the State Department denied Giuliani's request.

In cities that impose a congestion charge, the decision of some diplomatic missions not to furnish payment has proved controversial. In London, embassies have amassed approximately £58 million in unpaid charges as of 2012, with the American embassy comprising approximately £6 million and the Russian, German and Japanese missions around £2 million each.

Georgian driver in the United States
In January 1997, Giorgi Makharadze, a high-ranking Georgian diplomat, caused a five-car pileup in Washington, D.C., in the United States, which killed a 16-year-old girl. Makharadze's claim of diplomatic immunity created a national outrage in the United States, particularly given Makharadze's previous record of driving offenses: In April 1996, Makharadze had been charged with speeding in Virginia, and four months later, he was detained by District of Columbia police on suspicion of drunk driving. In both prior cases, charges were dismissed based on his immunity. On the basis of the media coverage, Georgia revoked Makharadze's immunity, and he was ultimately sentenced to seven years in prison after pleading guilty to one count of involuntary manslaughter and four counts of aggravated assault.

American driver in Russia
On 27 October 1998, in Vladivostok, Russia, Douglas Kent, the American Consul General to Russia, was involved in a car accident that left a young man, Alexander Kashin, disabled. Kent was not prosecuted in a US court. Under the Vienna Convention, diplomatic immunity does not apply to civil actions relating to vehicular accidents, but in 2006, the United States Court of Appeals for the Ninth Circuit ruled that, since he was using his vehicle for consular purposes, Kent could not be sued civilly.

Russian driver in Canada
In 2001, a Russian diplomat, Andrei Knyazev, hit and killed a woman while driving drunk in Ottawa. Knyazev refused to take a breathalyzer at the scene of the crash, citing diplomatic immunity. Russia refused Canadian requests to waive his immunity, and Knyazev was expelled from Canada. Though the Russian Foreign Ministry fired him and charged him with involuntary manslaughter, and Russian and Canadian authorities cooperated in the investigation, the case caused a political storm in Canada. Many accused the Foreign Ministry of incompetence after it emerged that Knyazev had twice been previously investigated for drunk driving. The Canadian Foreign Minister had fought unsuccessfully to have Knyazev tried in Ottawa. In 2002, Knyazev was found guilty of involuntary manslaughter in Russia.

American driver in Romania
On 3 December 2004, in Bucharest, Romania, Christopher Van Goethem, an American Marine serving his embassy, ran a red traffic signal, collided with a taxi, and killed popular Romanian musician Teo Peter. The Romanian government requested the American government to lift his immunity, which it refused to do. In a court-martial, he was acquitted of manslaughter and adultery but was convicted of obstruction of justice and making false statements.

Canadian driver in Tanzania
On 9 December 2009, in Tanzania, Canadian Junior Envoy Jean Touchette was arrested after it was reported that he spat at a traffic police officer on duty in the middle of a traffic jam in the Banana district on the outskirts of Dar es Salaam. Canada's High Commissioner, Robert Orr, was summoned by the Tanzanian Foreign Ministry over the incident, and the junior envoy was later recalled.

Romanian driver in Singapore
On 15 December 2009, in Singapore, the Romanian chargé d'affaires, Silviu Ionescu, was allegedly behind a drunk-driving hit-and-run accident that killed a 30-year-old man and seriously injured two others. He left Singapore for Romania three days after the accident. The Romanian foreign ministry suspended Ionescu from his post. A coroner's inquiry in Singapore, which included testimony by the Romanian embassy driver, concluded that Ionescu was solely responsible for the accident. An Interpol Red Notice was subsequently issued for his arrest and possible extradition notwithstanding the fact that Romania had not waived his diplomatic immunity and had commenced criminal proceedings against him in Romania. The Singapore government argued that by reason of Article 39(2) of the Vienna Convention, Ionescu was no longer protected by diplomatic immunity. Ionescu was eventually sentenced to six years in jail.

American driver in Pakistan
In January 2011 in Lahore, Pakistan, American embassy employee Raymond Allen Davis shot and killed two Pakistani civilians, while a third man was struck and killed by a US consulate car responding to the shooting. According to Davis, they were about to rob him and he acted in self-defense. When detained by police, Davis claimed to be a consultant at the US consulate in Lahore. He was formally arrested and remanded into custody. Further investigations revealed that he was working with the CIA as a contractor in Pakistan. The US State Department declared him a diplomat and repeatedly requested immunity under the Vienna Convention on Diplomatic Relations, to which Pakistan is a signatory. On 16 March 2011, Davis was released after the families of the two killed men were paid $2.4 million in diyya (a form of monetary compensation or blood money). Judges then acquitted him on all charges and Davis immediately departed Pakistan.

United Nations driver in Pakistan
On 10 April 2011, in Islamabad, Pakistan, Patrick Kibuta, an electrical engineer in the United Nations Military Observer Group in India and Pakistan caused a vehicle collision with another vehicle, while under the influence of alcohol. Kibuta, who was driving in the opposing lane, injured a Canadian citizen residing in Islamabad, who suffered multiple fractures and required surgery. The Kohsar police impounded Kibuta's UN vehicle on the scene, and a blood test confirmed that he had an elevated blood alcohol level. Charges for reckless and drunken driving were filed against Kibuta, who enjoyed diplomatic immunity.

American driver in Pakistan
On 14 February 2013, a vehicle bearing diplomatic plates registered to the US Embassy got into an accident in Islamabad, Pakistan involving two residents out of which one was killed and the other survived. Murder charges were laid under Section 320 of the Pakistani Penal Code against the driver of the vehicle who is a diplomat according to Pakistani officials.

American driver in Kenya
In July 2013, Joshua Walde, an American diplomat in Nairobi, Kenya, crashed into a mini-bus, killing one man and seriously injuring eight others, who were left with no financial assistance to pay for hospital bills. United States embassy officials took the diplomat and his family out of Kenya the following day. The United States government was concerned about the impact the accident could have on bilateral relations with Kenya. Walde gave a statement to police, but was not detained due to his diplomatic immunity. Kenyan police say the case remains under investigation.

Lebanese driver in South Korea
In September 2013, Jad Saeed al-Hassan, Lebanese Ambassador to South Korea, was involved in a hit-and-run in Seoul. Right after the accident, he drove directly into the Lebanese embassy compound and refused to cooperate with the local police investigation, claiming his diplomatic immunity. He stayed in his post as ambassador until his death due to another traffic collision in Seoul in 2014.

Qatari driver in the United States
On 12 September 2015, Sheikh Khalid bin Hamad Al Thani tried to claim diplomatic immunity when his Ferrari LaFerrari and a Porsche 911 GT3 were caught on camera drag racing through a residential neighborhood in Beverly Hills. He owns the cars and a drag racing team, and is a member of Qatar's ruling family. The Beverly Hills Police Department contacted the US State Department to clarify if he had diplomatic immunity. They stated he did not. However, his face was not shown on camera, and no officer witnessed the crime, so the state of California has not yet pressed charges. He has since fled the country. The investigation is ongoing.

Saudi driver in Germany
In June 2017, in Berlin, Germany a Saudi driver killed a cyclist by opening the door of his Porsche directly into the cyclist's path without checking to see if the road was clear. Anger arose when the Saudi claimed diplomatic immunity. Police said that under normal circumstances the driver would face investigation and possible prosecution on suspicion of negligent manslaughter, but prosecutors said they had no choice but to close the case because he had diplomatic immunity.

American driver in the United Kingdom
On 27 August 2019, Anne Sacoolas, the wife of an American government employee working in the United Kingdom, was a suspect in a traffic incident involving 19-year-old Harry Dunn in Croughton, Northamptonshire, England. Dunn was riding his motorcycle when it was reported that a woman emerged from RAF Croughton driving on the wrong side of the road, resulting in a head-on collision. After 999 handlers wrongly categorized the call, there was a 43-minute wait for an ambulance, resulting in a two-hour delay arriving at a trauma center, where Harry Dunn later died. Sacoolas was breathalyzed at the accident site. The following day, police interviewed Sacoolas at her home, learning the US claimed diplomatic immunity.

Sacoolas told police she had no immediate plans to leave the country. However, on 13 October US authorities notified the UK's Foreign and Commonwealth Office of plans to send Sacoolas home, unless serious objections were raised: on 16 October, the UK's Foreign Secretary, Dominic Raab, went to present objections, a day after the family was sent back.

Woody Johnson, U.S. Ambassador to the UK, expressed "profound sadness" at the death of Harry Dunn and the US Embassy also offered their sympathies and condolences. U.S. President Donald Trump called it a "terrible accident" and mentioned that the woman was "driving on the wrong side of the road, and that can happen". The US government has not waived the diplomatic immunity afforded to Sacoolas and has stated she would not return to the UK, despite calls by the UK government to do so.

Sacoolas was scheduled to appear in UK court via video link charged with causing the death of Mr Dunn by dangerous driving. A hearing took place in Westminster Magistrates Court on the 18th January 2022. She appeared by video-link at the Old Bailey, where she pleaded guilty to causing death by careless driving on 20 October 2022. She was handed an eight-month jail term, suspended for 12 months, and was also disqualified from driving for 12 months.

Financial abuse
Historically, large debts run up by diplomats has caused many problems. Some financial institutions do not extend credit to diplomats because they have no legal means of ensuring the money be repaid. Local citizens and businesses are often at a disadvantage when filing civil claims against a diplomat, especially in cases of unpaid rent, alimony, and child support.

Rents
The bulk of diplomatic debt lies in the rental of office space and living quarters. Individual debts can range from a few thousand dollars to $1 million in back rent. A group of diplomats and the office space in which they work are referred to as a diplomatic mission. Creditors cannot sue missions individually to collect money they owe. Landlords and creditors have found that the only thing they can do is contact a city agency to see if they can try to get some money back. They cannot enter the offices or apartments of diplomats to evict them because the Foreign Sovereign Immunities Act says that "the property in the United States of a foreign state shall be immune from attachment, arrest and execution". This has led creditors who are owed money by diplomats to become more cautious about their renters and to change their rental or payment policies.

In one case, for example, officials from Zaire stopped paying rent to their private landlord and ran up $400,000 in debt. When the landlord sued, the US State Department defended the Zaireans on the basis of diplomatic immunity, and a circuit court agreed. When the landlord finally cut off the utilities, the officials fled without paying their back rent. The landlords reportedly later reached an "amicable agreement" with the Zairean government.

Alimony and child support
The issue of abusing diplomatic immunity in family relations, especially alimony and child support, has become so widespread that it prompted discussion at the 1995 UN Fourth World Conference on Women, in Beijing. Historically, the United Nations has not become involved with family disputes and has refused to garnish the wages of diplomats who owe money for child support, citing sovereign immunity. However, in September 1995, the incumbent head of Legal Affairs for the United Nations acknowledged there was a moral and legal obligation to take at least a partial responsibility in family disputes. Fathers working as diplomats who refused to fulfill their family-related financial duties were increasing in numbers in the United Nations: several men who had left their wives and children were still claiming UN dependency, travel, and education allowances for their families, though they are no longer supporting those families.

Taxes and fees
Diplomats are exempt from most taxes, but not from "charges levied for specific services rendered". In certain cases, whether a payment is or is not considered a tax may be disputed, such as central London's congestion charge. It was reported in 2006 that the UAE embassy had agreed to pay their own accumulated charges of nearly £100,000.

There is an obligation for the receiving state not to "discriminate as between states"; in other words, any such fees should be payable by all accredited diplomats equally. This may allow the diplomatic corps to negotiate as a group with the authorities of the receiving country.

Diplomats are exempt from import duty and tariffs for items for their personal use. In some countries, this has led to charges that diplomatic agents are profiting personally from resale of "tax free" goods. The receiving state may choose to impose restrictions on what may reasonably constitute personal use (for example, only a certain quantity of cigarettes per day). When enacted, such restrictions are generally quite generous so as to avoid tit-for-tat responses.

Money laundering
United States v. Al Sharaf is a criminal case which was filed by the government on March 5, 2015 in the United States District Court for the District of Columbia. Al Sharaf was a Kuwaiti Financial Attaché assigned to handle the finances of Kuwait Health Office in Washington, D.C. She was charged by the government as she had violated 18 U.S.C § 1956 for conspiring to launder money. Al Sharaf filed a motion to dismiss the case on the basis of lack of subject matter jurisdiction because as per the 22 U.S.C § 254d her actions were immune under the diplomatic immunity that she had. Since it was a criminal case, the prosecution presented evidence beyond a reasonable doubt to prove that Al Sharaf had engaged in commercial activity and her actions were different from her official functions as a representative of Kuwait, thereby, as per the VCDR art. 31(c) her diplomatic immunity was subject to waiver. The court ruled in prosecution's favor and stated that since the defendant had engaged in commercial activity which was different from her official functions, her diplomatic immunity was subject to waiver and hence the defendant's motion to dismiss the case on the basis of lack of subject matter jurisdiction was denied.

Espionage and sabotage
Franz von Papen entered the diplomatic service in December 1913 as a military attaché to the German ambassador in the United States. Starting in September 1914, Papen abused his diplomatic immunity as German military attaché, violating US laws to start organising plans for incursions into Canada for a campaign of sabotage against canals, bridges and railroads. In October 1914, Papen became involved with what was later dubbed "the Hindu–German Conspiracy", by covertly arranging with Indian nationalists based in California for arms trafficking to the latter for a planned uprising against the British Raj. In February 1915, Papen also covertly organised the Vanceboro international bridge bombing, in which his diplomatic immunity protected him from arrest. At the same time, he remained involved in plans to restore Huerta to power, and arranged for the arming and financing of a planned invasion of Mexico. Papen's covert operations were known to British intelligence, which shared its information with the US government. As a result, for complicity in the planning of acts of sabotage on 28 December 1915, Captain von Papen was declared persona non grata and recalled to Germany. Upon his return, he was awarded the Iron Cross.

On 24 April 2008, in New Orleans, Mexican press attaché Rafael Quintero Curiel was seen stealing BlackBerry PDA units from a White House press meeting room. Quintero made it all the way to the airport before members of the United States Secret Service caught up with him. He initially denied taking the devices, but after being confronted with security video, Quintero claimed it was purely accidental, gave the devices back, claimed diplomatic immunity and left New Orleans with the Mexican delegation. He was eventually fired for the incident.

In 2021, it was reported that the UAE Embassy in Canberra was building non-compliant fences and installing CCTV.

In the United States
The following chart outlines the immunities afforded to foreign diplomatic personnel residing in the United States. In general, these rules follow the Vienna Convention (or the New York Convention for UN officials) and apply in other countries as well (with the exceptions of immunities for United Nations officials, which can vary widely across countries based on the "Host Country Agreement" signed between the UN and the host country, whereby additional immunities beyond those granted by the New York Convention may be established).

title: Diplomatic immunity


text:
DDR SDRAM

Double Data Rate Synchronous Dynamic Random-Access Memory (DDR SDRAM) is a double data rate (DDR) synchronous dynamic random-access memory (SDRAM) class of memory integrated circuits used in computers. DDR SDRAM, also retroactively called DDR1 SDRAM, has been superseded by DDR2 SDRAM, DDR3 SDRAM, DDR4 SDRAM and DDR5 SDRAM. None of its successors are forward or backward compatible with DDR1 SDRAM, meaning DDR2, DDR3, DDR4 and DDR5 memory modules will not work on DDR1-equipped motherboards, and vice versa.

Compared to single data rate (SDR) SDRAM, the DDR SDRAM interface makes higher transfer rates possible through more strict control of the timing of the electrical data and clock signals. Implementations often have to use schemes such as phase-locked loops and self-calibration to reach the required timing accuracy. The interface uses double pumping (transferring data on both the rising and falling edges of the clock signal) to double data bus bandwidth without a corresponding increase in clock frequency. One advantage of keeping the clock frequency low is that it reduces the signal integrity requirements on the circuit board connecting the memory to the controller. The name "double data rate" refers to the fact that a DDR SDRAM with a certain clock frequency achieves nearly twice the bandwidth of a SDR SDRAM running at the same clock frequency, due to this double pumping.

With data being transferred 64 bits at a time, DDR SDRAM gives a transfer rate (in bytes/s) of (memory bus clock rate) × 2 (for dual rate) × 64 (number of bits transferred) / 8 (number of bits/byte). Thus, with a bus frequency of 100 MHz, DDR SDRAM gives a maximum transfer rate of 1600 MB/s.

History
In the late 1980s IBM had built DRAMs using a dual-edge clocking feature and presented their results at the International Solid-State Circuits Convention in 1990.

Samsung demonstrated the first DDR memory prototype in 1997, and released the first commercial DDR SDRAM chip (64Mbit) in June 1998,  followed soon after by Hyundai Electronics (now SK Hynix) the same year. The development of DDR began in 1996, before its specification was finalized by JEDEC in June 2000 (JESD79). JEDEC has set standards for the data rates of DDR SDRAM, divided into two parts. The first specification is for memory chips, and the second is for memory modules. The first retail PC motherboard using DDR SDRAM was released in August 2000.

Modules
To increase memory capacity and bandwidth, chips are combined on a module. For instance, the 64-bit data bus for DIMM requires eight 8-bit chips, addressed in parallel. Multiple chips with common address lines are called a memory rank. The term was introduced to avoid confusion with chip internal rows and banks. A memory module may bear more than one rank. The term sides would also be confusing because it incorrectly suggests the physical placement of chips on the module. All ranks are connected to the same memory bus (address + data). The chip select signal is used to issue commands to specific rank.

Adding modules to the single memory bus creates additional electrical load on its drivers. To mitigate the resulting bus signaling rate drop and overcome the memory bottleneck, new chipsets employ the multi-channel architecture.

Note: All items listed above are specified by JEDEC as JESD79F. All RAM data rates in-between or above these listed specifications are not standardized by JEDEC – often they are simply manufacturer optimizations using tighter tolerances or overvolted chips. The package sizes in which DDR SDRAM is manufactured are also standardized by JEDEC.

There is no architectural difference between DDR SDRAM modules. Modules are instead designed to run at different clock frequencies: for example, a PC-1600 module is designed to run at 100 MHz, and a PC-2100 is designed to run at 133 MHz. A module's clock speed designates the data rate at which it is guaranteed to perform, hence it is guaranteed to run at lower (underclocking) and can possibly run at higher (overclocking) clock rates than those for which it was made.

DDR SDRAM modules for desktop computers, dual in-line memory modules (DIMMs), have 184 pins (as opposed to 168 pins on SDRAM, or 240 pins on DDR2 SDRAM), and can be differentiated from SDRAM DIMMs by the number of notches (DDR SDRAM has one, SDRAM has two). DDR SDRAM for notebook computers, SO-DIMMs, have 200 pins, which is the same number of pins as DDR2 SO-DIMMs. These two specifications are notched very similarly and care must be taken during insertion if unsure of a correct match. Most DDR SDRAM operates at a voltage of 2.5 V, compared to 3.3 V for SDRAM. This can significantly reduce power consumption. Chips and modules with the DDR-400/PC-3200 standard have a nominal voltage of 2.6 V.

JEDEC Standard No. 21–C defines three possible operating voltages for 184 pin DDR, as identified by the key notch position relative to its centreline. Page 4.5.10-7 defines 2.5V (left), 1.8V (centre), TBD (right), while page 4.20.5–40 nominates 3.3V for the right notch position. The orientation of the module for determining the key notch position is with 52 contact positions to the left and 40 contact positions to the right.

Increasing the operating voltage slightly can increase maximum speed but at the cost of higher power dissipation and heating, and at the risk of malfunctioning or damage.

 * Capacity
 * Number of DRAM devices: The number of chips is a multiple of 8 for non-ECC modules and a multiple of 9 for ECC modules. Chips can occupy one side (single sided) or both sides (dual sided) of the module. The maximal number of chips per DDR module is 36 (9×4) for ECC and 32 (8x4) for non-ECC.
 * ECC vs non-ECC: Modules that have error-correcting code are labeled as ECC. Modules without error correcting code are labeled non-ECC.
 * Timings: CAS latency (CL), clock cycle time (tCK), row cycle time (tRC), refresh row cycle time (tRFC), row active time (tRAS).
 * Buffering: Registered (or buffered) vs unbuffered.
 * Packaging: Typically DIMM or SO-DIMM.
 * Power consumption: A test with DDR and DDR2 RAM in 2005 found that average power consumption appeared to be of the order of 1–3 W per 512 MB module; this increases with clock rate and when in use rather than idling. A manufacturer has produced calculators to estimate the power used by various types of RAM.

Module and chip characteristics are inherently linked.

Total module capacity is a product of one chip's capacity and the number of chips. ECC modules multiply it by $RCD$ because they use 1 bit per byte (8 bits) for error correction. A module of any particular size can therefore be assembled either from 32 small chips (36 for ECC memory), or 16(18) or 8(9) bigger ones.

DDR memory bus width per channel is 64 bits (72 for ECC memory). Total module bit width is a product of bits per chip and number of chips. It also equals number of ranks (rows) multiplied by DDR memory bus width. Consequently, a module with a greater number of chips or using ×8 chips instead of ×4 will have more ranks.

This example compares different real-world server memory modules with a common size of 1 GB. One should definitely be careful buying 1 GB memory modules, because all these variations can be sold under one price position without stating whether they are ×4 or ×8, single- or dual-ranked.

There is a common belief that number of module ranks equals number of sides. As above data shows, this is not true. One can also find 2-side/1-rank modules. One can even think of a 1-side/2-rank memory module having 16(18) chips on single side ×8 each, but it is unlikely such a module was ever produced.

Chip characteristics

 * DRAM density: Size of the chip is measured in megabits. Most motherboards recognize only 1 GB modules if they contain 64M×8 chips (low density). If 128M×4 (high density) 1 GB modules are used, they most likely will not work. The JEDEC standard allows 128M×4 only for registered modules designed specifically for servers, but some generic manufacturers do not comply.
 * Organization: The notation like 64M×4 means that the memory matrix has 64 million (the product of banks x rows x columns) 4-bit storage locations. There are ×4, ×8, and ×16 DDR chips. The ×4 chips allow the use of advanced error correction features like Chipkill, memory scrubbing and Intel SDDC in server environments, while the ×8 and ×16 chips are somewhat less expensive. x8 chips are mainly used in desktops/notebooks but are making an entry into the server market. There are normally 4 banks and only one row can be active in each bank.

Double data rate (DDR) SDRAM specification
From Ballot JCB-99-70, and modified by numerous other Board Ballots, formulated under the cognizance of Committee JC-42.3 on DRAM Parametrics.

Standard No. 79 Revision Log:
 * Release 1, June 2000
 * Release 2, May 2002
 * Release C, March 2003 – JEDEC Standard No. 79C.

"This comprehensive standard defines all required aspects of 64Mb through 1Gb DDR SDRAMs with X4/X8/X16 data interfaces, including features, functionality, ac and dc parametrics, packages and pin assignments. This scope will subsequently be expanded to formally apply to x32 devices, and higher density devices as well."

Organization
PC3200 is DDR SDRAM designed to operate at 200 MHz using DDR-400 chips with a bandwidth of 3,200 MB/s. Because PC3200 memory transfers data on both the rising and falling clock edges, its effective clock rate is 400 MHz.

1 GB PC3200 non-ECC modules are usually made with 16 512 Mbit chips, 8 on each side (512 Mbits × 16 chips) / (8 bits (per byte)) = 1,024 MB. The individual chips making up a 1 GB memory module are usually organized as 226 8-bit words, commonly expressed as 64M×8. Memory manufactured in this way is low-density RAM and is usually compatible with any motherboard specifying PC3200 DDR-400 memory.

Generations
DDR (DDR1) was superseded by DDR2 SDRAM, which had modifications for a higher clock frequency and again doubled throughput, but operates on the same principle as DDR. Competing with DDR2 was Rambus XDR DRAM. DDR2 dominated due to cost and support factors. DDR2 was in turn superseded by DDR3 SDRAM, which offered higher performance for increased bus speeds and new features. DDR3 has been superseded by DDR4 SDRAM, which was first produced in 2011 and whose standards were still in flux (2012) with significant architectural changes.

DDR's prefetch buffer depth is 2 (bits), while DDR2 uses 4. Although the effective clock rates of DDR2 are higher than DDR, the overall performance was not greater in the early implementations, primarily due to the high latencies of the first DDR2 modules. DDR2 started to be effective by the end of 2004, as modules with lower latencies became available.

Memory manufacturers stated that it was impractical to mass produce DDR1 memory with effective transfer rates in excess of 400 MHz (i.e. 400 MT/s and 200 MHz external clock) due to internal speed limitations. DDR2 picks up where DDR1 leaves off, utilizing internal clock rates similar to DDR1, but is available at effective transfer rates of 400 MHz and higher. DDR3 advances extended the ability to preserve internal clock rates while providing higher effective transfer rates by again doubling the prefetch depth.

The DDR4 SDRAM is a high-speed dynamic random-access memory internally configured as 16 banks, 4 bank groups with 4 banks for each bank group for ×4/×8 and 8 banks, 2 bank groups with 4 banks for each bank group for ×16 DRAM. The DDR4 SDRAM uses an 8n prefetch architecture to achieve high-speed operation. The 8n prefetch architecture is combined with an interface designed to transfer two data words per clock cycle at the I/O pins. A single read or write operation for the DDR4 SDRAM consists of a single 8n-bit-wide 4-clock data transfer at the internal DRAM core and 8 corresponding n-bit-wide half-clock-cycle data transfers at the I/O pins.

RDRAM was a particularly expensive alternative to DDR SDRAM, and most manufacturers dropped its support from their chipsets. DDR1 memory's prices substantially increased from Q2 2008, while DDR2 prices declined. In January 2009, 1 GB DDR1 was 2–3 times more expensive than 1 GB DDR2.

Mobile DDR
MDDR is an acronym that some enterprises use for Mobile DDR SDRAM, a type of memory used in some portable electronic devices, like mobile phones, handhelds, and digital audio players. Through techniques including reduced voltage supply and advanced refresh options, Mobile DDR can achieve greater power efficiency.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: DDR SDRAM


text:
Talk:DDR SDRAM

"high density"
The only source given as evidence for this is a non-editorial, unreliable source - eBay reviews. Can anyone confirm or deny by providing better evidence? 22:42, 23 Oct 2010 (UTC) —Preceding unsigned comment added by 89.240.113.195 (talk)

 * Yes, I agree, a more reliable source is necessary. There are many different explanations of high/low density out there, which I guess causes a lot of confusion. Is a bad sign, that in 5 years nobody added a source? — Preceding unsigned comment added by Esel7353 (talk • contribs) 22:48, 28 April 2015 (UTC)

Minimum speed?
All dynamic RAM has a minimum speed at which it must be clocked in order to retain data. I'd like to see minimum frequency figures for various DDR RAM types. This information is important when underclocking. And it determines whether newer RAM can be used in older systems.

edge
There needs to be an explanation of what is meant by an "edge" as in a clock edge. Preferably that explanation should go on its own page then be referred also from the page that talks about edge triggered interrupts, and the edge detection in image processing page

Vandalism
Looks like someone has been vandalizing this page. Can anyone revert a page, or must an administrator do so?
 * Anyone can do it, although admins can use a shortcut. Everyone else can just go to the edit history, open the last good version and then save it. I have fixed the vandalism you referred to. --Heron 21:34, 15 Jun 2005 (UTC)

"Rambus memory (RDRAM®) is a revolutionary step from SDRAM" Please NPOVify such statements. --Taw

It would be nice if someone would say whether DDR modules are backward compatible; ie if I can use DDR333 in a DDR266 motherboard. Thue

AFAIK, there are some speeds not listed: PC3500 (433 MHz), PC4000 (500 MHz), and PC4400 (550 MHz). --Ubern00b 19:34, 21 Sep 2004 (UTC)

I removed all speeds higher than DDR400, as none of these are JEDEC standards. They're simply overclocked DDR400. I removed mentions of quad-channel DDR, as I've never seen or heard of it used, if anyone has cites that would be great. I removed mention of QDR and Quad-Band as competitors, as neither ever materialized as products. Alereon 06:28, Nov 9, 2004 (UTC)

I have merged DDR RAM with this one and placed a redirect instead.

What about DDR2 RAM? It's worth a mention don't you think?

hi could someone please write an explanation on this page of pc2 chips? and if possible talk about the various chips found on ddr and their tolerance to overclocking perhaps ( the TCCD and UCCC chips) i would be grateful. thx.

Upgrading
1)When upgrading a computer that already has a memory stick by adding another stick, what considerations does one have to make? 2)Can you mix sticks with different latencies? 3)Can you mix single sided with double sided? 4)Can you mix different brands?

not sure when this question was asked but answers: 1) brands supported by your motherboard, size and speed supported by your BIOS 2) yes, most of the time 3) yes, sometimes. This is governed by your motherboard not the memory. Some motherboards allow dual-sided memory in only certain slots or not at all. This should be in your motherboard manual. 4) yes. no problems if #1 is followed through. 70.20.252.106 (talk) 18:56, 28 February 2008 (UTC)

Single-sided vs. dual-sided?
I vaguely understand that there are differences between single-sided vs. dual-sided DIMMS, am I correct? Can someone explain the differences?

Thanks. Penedo 05:11, 31 August 2006 (UTC)

 * Double sided, better called double-row, memory requires more organisation from the memory controller as it usually has more chips than single-sided, better called single-row, memory. 512MB sticks usually have 8 chips in single and 16 chips in dual, the memory controller has to adress all chips (less work to adress only 8 chips). Additional info: single/double refers to the internal organisation but not to the external mounting of the memory chips. It is possible to have have 8-chip (4 per side) sticks but internally single-sided (rowed).

 * Thanks for the explenation. Is there a definite way to find out from a chip's specification or the way it looks whether it's Double-row or Single-row? I raise the question because I was bitten by buying a double-row memory module which didn't work with my motherboard because, as it turned out, it supports only single-row (or maybe I hit the limit of rows that MoBo supports? I don't know. Someone on the net told me that maybe what counts for the MoBo (or the memory controller) is the total number of rows, no matter how many memory modules they are spread over). Penedo 07:04, 1 September 2006 (UTC)

 * I added explanation of this issue to the page under sections "Chip characteristics" and "Module characteristics". Hope it's intelligible and helpful. I had the same problem of identifying chips recently and didn't find info at Wiki, so here it is finally. As I state in the article one should not mix notions of number of rows (ranks) and number of sides, because they are not-so-tightly connected. Alexander Abramov 16:32, 13 October 2006 (UTC)

 * This "row" terminology for number of sides seems really unfortunate considering that each chip has rows (a different kind) and columns (and banks, I think). DHR 21:12, 19 November 2006 (UTC)

Is there anywhere that has a good explaination of how ddr and ddr 2 is accessed (IE, how does the northbridge exchange data between the two types of memory?) From my limited reading, I believe that the bus size in most computers is 64 bits, so data is transfered at 100 mhz but 4 bytes are transfered, or the same as transfering 1 eight bit word (byte) at 400 mhz. How is ddr two different, or is it truly just a faster transfer rate? I saw a intel presentation that seemed to show serial data transfer. Can someone point me in the right direction?
 * DDR uses both edges of the clock to perform transfers so a 100mhz clock gives 200 megatransfers per second. If each transfer is 4 bytes wide (which I belive it is with standard PC memory modules) that mean 800 megabytes per second.

DDR 533
does this version exist? or the top model is the ddr400? --83.190.159.64 18:47, 13 April 2007 (UTC)
 * Only as self-made specification by several OC memory manufacturers like Kingston, OCZ etc. Usually heavily overvolted standard memory. Not an official specification thus not in the overview. --Denniss 06:07, 14 April 2007 (UTC)
 * I think it should still be included —Preceding unsigned comment added by 66.194.72.10 (talk • contribs)
 * I tend to agree that it deserves a mention, properly noted that it's unofficial. Limiting the article to only the official versions edges on NPOV -- RoninBK T C 20:03, 29 December 2007 (UTC)

 * We have this home-brewed stuff alredy as a small note in the article: Note: All above listed are specified by JEDEC as JESD79. All RAM speeds in-between or above these listed specifications are not standardized by JEDEC — most often they are simply manufacturer optimizations using higher-tolerance or overvolted chips.
 * If we start to include this non-standard then we soon have some IPs adding all the BS inbetween "designed" by all the different manufacturers. That's why we stick to the official, well documented, specifications. The same applies to the DDR2 and DDR3 articles. --Denniss (talk) 01:17, 30 December 2007 (UTC)
 * I did see that mention after the edit I made. It is awfully short and easily overlooked by someone, (ok myself,) looking to Wikipedia to figure out "What is this PC4000 stuff that this manufacturer is talking about?" I do understand the point you make, I'm just saying a one paragraph subsection, something like "Unofficial specifications", would be a welcome addition. -- RoninBK T C 09:59, 31 December 2007 (UTC)

Chronology
Can we get some information about the years (circa) during which each type of RAM was typical? This would really help people trying to place older hardware in a historical context. Something like, "DDR1 ram was typically supported on motherboards sold from 199x to 200x" would be a very useful piece of information.

memory "DDR maximum capacity"
I read that the DDR memory maximum capacity is 1 Gigabyte por module. I think it should be checked and added to the entry if true. —Preceding unsigned comment added by 84.125.128.144 (talk) 13:45, 6 January 2008 (UTC)

DDR 300
Hi. I have re-added DDR 300 to the list, as another user deleted it, despite sources having been cited showing it exists. Does it belong in the article or not? Comments please. Thanks! --Rebroad (talk) 13:45, 2 March 2008 (UTC)
 * DDR-300 may exist but not as standard, that's only home-brewed stuff by some manufacturers. Have you ever read the small note below the table? Also i linked the recent JEDEC DDR-SDRAM specification (you may have missed this also as it specifically notes the cycle times). --Denniss (talk) 16:06, 2 March 2008 (UTC)
 * Ok, it exists but is not a JEDEC-standard. Therefore it needs to be mentioned, but the foot-note corrected, which I have now done. I don't know why you couldn't have done this yourself, rather than simply deleting it. --Rebroad (talk) 02:26, 4 March 2008 (UTC)
 * I have removed it again. If you want to list non-standardized "specifications" then search and list them all but under a different heading. If you continue to remove the link to the current JESD79E DDR-SDRAM standard it may be counted as vandalism or disruptive behaviour. IF you read this spec you won't find DDR-300 but, surprisingly, the cycle time you want to have a ref for. --Denniss (talk) 13:09, 4 March 2008 (UTC)

Denniss, if you have an issue with the heading, then change it. As it stands, I don't have an issue with it, as it is "specifications and standards", and DDR-300 HAS a specification, therefore it belongs. It is now mentioned that it is not part of the JEDEC standard, so I do not understand why you keep deleting it altogether. It is DDR SDRAM, is it not? Therefore whether JEDEC standard or not, it belongs in the article. I would understand your deletion if the article name was "JEDEC standard DDR SDRAM", but, it is not, so therefore, please explain your deletions. --Rebroad (talk) 09:46, 5 March 2008 (UTC)

Denniss, apologies, the deletion of the reference was accidental. Please remember WP:AGF. I am also assuming your deletions of the cn tags was also accidental (as per the timings section below). --Rebroad (talk) 09:49, 5 March 2008 (UTC)

 * Is DDR-300 listed in the JESD79 specification? No so it's no standard. As with those other ones like DDR-433 it's something home-brewed and far from any standardization. The same goes for PC-150 (SDR-SDRAM operation at 150 MHz just like your DDR-300 "standardd") - not a standard. --Denniss (talk) 15:33, 5 March 2008 (UTC)

Denniss, I don't know why you typed that. Did you read what I wrote above? --Rebroad (talk) 17:17, 6 March 2008 (UTC)

I'm not actively involved with this article and I don't want to get into a revert war over this apparently contentious issue. But if DDR300 is to be included in the chart, then all the other non-standard speeds should also be included. If that's the decision, then the JEDEC speeds should be clearly distinguished in the chart. As it stands, the special mention of DDR300 (at the exclusion of other nonstandard speeds) is confusing and potentially misleading about the nature of DDR300. It's nice that the non-JEDEC issue is mentioned in the small print, but the choice of items on the chart still doesn't make sense. -Greg 00:26, 30 Jul 2008 (UTC)

I've added a column in the chart for standard operating voltage of each speed grade. There is some variety of voltages on the labeling of different memory modules, especially with overclocked gamer ram, so it's useful to note what the standards are. There's an interesting change with DDR400, where JEDEC officially standardized a higher nominal voltage of 2.6v, while tightening the tolerances to only +/- 0.1v. This is indicated in JESD79E pg45. -Greg 00:43, 30 Jul 2008 (UTC)

Timings
Hi. Anyone know where the timing figures came from please? I couldn't find mention of them on the web, so I've added citation requests until a source can be found. These tags should not be removed until a reference is found and added to the article, otherwise the timings themselves can be deleted from the article if no sources are available, as wikipedia is not a place for original research, as per policy WP:NOR. --Rebroad (talk) 02:29, 4 March 2008 (UTC)

 * Dude, 10 ns = 1/(100 MHz). ;-)  58.165.156.75 (talk) 12:19, 13 March 2008 (UTC)

 * It looks like Rebroad is not able or not willing to read the JEDEC specifiation as it clearly mentions the cycle time. BTW the DDR-300/PC-2400 is original research.--Denniss (talk) 20:01, 13 March 2008 (UTC)
 * Anyone know where the timing figures came from please? - yeah ... from math science ;)) Lothar25 (talk) 20:15, 30 March 2008 (UTC)

Production Period
Is DDR still in production? Checking market prices for 1 GB DIMMs it was March 2007 when DDR2 costed about as much as DDR ($60/GB street price). In March 2008 DIMM prices are about half ($30/GB), while DDR2 prices are about one quarter ($15/GB) - and the price drop for SO-DIMMs is much less than for DIMM ($50/GB), while the DDR2 prices for SO-DIMM are almost the same ($16/GB). Thus I wonder whether DDR2 is in mass production nowadays and DDR is out of production, but remaining stock only. --Traut (talk) 18:26, 18 March 2008 (UTC)

4 ranks for 1 DIMM?
From waht I know, there are no DDR1-DIMMs which have more than 2 ranks. I also know of no memory-controller, which supports more then 2 ranks per DDR1-DIMM. --MrBurns (talk) 03:31, 6 November 2008 (UTC)

Wrong picture top right?
It might be that the image shown top right is actually (I think 184 pinn) DIMM ram. I suspect, because DIMM has a little hole around the bottom center, while DDR ram has 2 holes (one around the bottom center and one around the bottom right). —Preceding unsigned comment added by 71.206.65.120 (talk) 22:19, 27 March 2009 (UTC)

prefixes
is the size of ram specified using normal SI prefixes or is it the convention to use the binary prefixes? I would suspect the last, but I'm not sure on this. if so It would be nice, and much more correct to use the correct binary prefixes MiB (mebibyte: 2^20) instead of MB (megabyte: 10^3) see:
 * Mebibyte
 * Nist
 * IEC —Preceding unsigned comment added by 81.83.89.102 (talk) 10:39, 25 April 2009 (UTC)

I started changing this where i was pretty sure. Replaced MB with MiB etc in the paragraph Chip Characteristics / DRam Density, but then i was unsure about the correct sumbols in the High Density vs Low Density paragraph. Could someone please look into that one! Thanks!

--Burt777 (talk) 09:00, 15 September 2009 (UTC)

History
Hi, can someone who knows add stuff about when it was first introduced, when it was widely adopted etc.? —Preceding unsigned comment added by 83.146.12.224 (talk) 19:37, 3 June 2009 (UTC)

What about adding a small section about RAMBUS litigation claiming DDR violates their patents? There's a small unclear section in RAMBUS entry mentioning DDR. —Preceding unsigned comment added by 99.235.238.24 (talk) 08:40, 14 June 2009 (UTC)

How is supply voltage controlled?
The article says weird things about the Vcc/Vdd supply voltage. SPD Byte 8 specifies the Voltage Interface Level; Byte 22 specifies some Vcc tolerances. How do 184-pin DDR SDRAM modules specify the Vcc supply voltage? It seems like the mainboards must be able to read something from the memory modules and know what voltage should be supplied. The article makes it sound sort of auto-magical, various voltages for various speeds. But when buying RAM, different modules at the same speeds spec different voltages (2.5V and 2.6V most common) -- it seems like there must be some hardware features that are supposed to make this all work together properly.

I would guess that some BIOS setup programs allow reading out the actual RAM voltage level, and doing a manual over-ride to change the supply voltage. It seems like the article should mention this aspect. -71.174.180.142 (talk) 21:16, 15 July 2009 (UTC)

This discussion: says that some mainboards had jumpers that controlled the SDRAM supply voltage. -71.174.180.142 (talk) 21:28, 15 July 2009 (UTC)
 * www.tomshardware.com/forum/111604-30-a7m266-memory-voltage-warning

Pinouts
This article is still quite skimpy, for such a core tech article!

We need some detailed pinout tables, or at least clear links to such info.

We need a picture of a standard laptop So-DIMM (200pin?)

We need a list/table of all the standard physical embodiments of DDR SDRAM, listing dimensions, number of pins, usage, etc -- ideally with a pic of each. -96.237.5.115 (talk) 12:54, 16 July 2009 (UTC)

(anonymous user, 1/25/2011): A picture of an SDR module and a DDR module should be shown next to each other, and some text explaining they are absolutely NOT compatible. Also that the older SDR modules have 168 pins and are keyed TWICE (two notches) and DDR modules have 184 pins and are keyed ONCE. —Preceding unsigned comment added by 69.123.175.176 (talk) 16:48, 25 January 2011 (UTC)

JEDEC module standards
The article has links to JEDEC standards for chips. It says that there are also JEDEC standards for the DIMM modules. But what are the actual specific titles of those standards, and where are they?-96.237.5.115 (talk) 14:08, 16 July 2009 (UTC)

SDR designation
I noticed the abbreviation "SDR" being used to define "single data rate" in the beginning of the article. But this term is redundant, ram was never referred to as single data rate. That is a definition about it that came after double data rate technology was developed. Language may be confused with the abbreviation of synchronous dynamic ram. Suggest revising, unless there is some particular reason for keeping it.

"Chips and Modules" Section
Why was the "Chips and Modules" section removed from this article? I found the reference chart linking each DDR type with its PC-XXXX and DDR-XXX terminologies extremely helpful and used it on a regular basis. I'd love to see it re-added so I don't have to look constantly at the article's history.

 * Result of Vandalism - restored. --Denniss (talk) 23:24, 24 April 2010 (UTC)

Calling DDR Ram "DDR SD RAM"
I have always in my own head thought of SD RAM as 168 PIN Dimms PC100 / PC133. I have never called DDR Ram "DDR SD RAM" Neither have any of my friends. Can we eliminate the SD nomenclature since its not sd ram, its DDR ram? there is nothing SD about it!
 * It is SDRAM although modified with an DDR interface. Even DDR3 and GDDR5 belong to the SDRAM family. --Denniss (talk) 15:33, 28 April 2010 (UTC)

Typical areas where ECC / Non-ECC are used
The section about ECC vs non-ECC could be expanded a bit: 1. In many cases, ECC-memory has 9 memory circuits, where Non-ECC has 8. 2. ECC memory can mostly be found in servers and Macintosh systems. 3. These memory types can't replace each other. First of all, I'm not 100% on these things, that's why I write here on the talk-page. And, it would be good to support these facts with good references. TobiF (talk) 17:14, 23 May 2010 (UTC)

How To Install DDR Memory
A lot of people don't seem to know how to install memory modules and get a bit confused as to what modules their system can take.

There's a video here showing how to install DDR memory modules - http://www.eteknix.com/how-s/how-install-ddr-memory-modules-121/

Clears things up for a lot of users i feel. —Preceding unsigned comment added by Aruffell (talk • contribs) 09:43, 19 November 2010 (UTC)

STOP CALLING IT SDRAM!!!!!
ITS CALLED DDR RAM! SD RAM SPECIFICALLY REFERS TO 168 PIN 3.3v DIMMS. AT WORK WHEN I ASK FOR RAM I ASK CAN I HAVE SOME DDR? OR CAN I HAVE A 256 STICK OF DDR2? I NEVER REFER TO IT AS SDRAM. IF I WANT a 128 —Preceding unsigned comment added by 173.15.42.13 (talk) 22:31, 5 April 2011 (UTC)
 * But it is a form of SDRAM. No-one here is interested in what you call it when you are at work: we are interested in reliable sources and correctness, not misconceptions. Crispmuncher (talk) 23:29, 5 April 2011 (UTC)
 * Stop calling our stuff DDR RAM. It is called DDR  SD RAM! Your bullsit is not SDRAM! But, I'm not opposed to a couple of words to resolve the confusion that really exists. People indeed do not understand that DDR is an advanced interface to SDRAM. --Javalenok (talk) 09:45, 6 April 2011 (UTC)

 * In fact this article confuses me since technical sources I read make a marked distinction between DDR and SDRAM. Medende (talk) 16:00, 7 June 2012 (UTC)

IIRC DDR is SDRAM that is clocked twice hence the name double data rate. — Preceding unsigned comment added by 74.103.202.201 (talk) 14:34, 5 September 2014 (UTC)

Rank confusion with baks
These two are easy to confuse. And this is happened in the article, IMO. The one who wrote about Ranks in the 'module organization' section warns us about the rank confusion with rows and sides. Nevertheless, it seems that he confuses the ranks with banks himself: "Any given module can have 1, 2, or 4 ranks, but only 1 rank of a module can be active at any moment in time. When a module has two or more ranks, the memory controller must periodically switch between them by performing close and open operations." This is behaviour of banks, IMO, not DIMM module ranks. I see that two-rank DIMMs have two CS inputs. This allows free addressing both ranks at a time. I do not see how DIMM connects the inputs to CS of the chips, though. Is there a decoder that selects only one rank depending on /S0/S1 code or it is the spec that prohibits assigning both /S0 and /S1 to 0? --Javalenok (talk) 11:12, 9 April 2011 (UTC)

Chips vs modules
I think this article jumps between describing individual DDR SDRAM components and DDR DIMM:s in a slightly confusing way. It should be reorganized into a chip/technology part and a DIMM/PC system part, as they are both standardized separately by JEDEC. DDR memory is also used quite a lot for embedded applications, often with components soldered directly to the computer board rather than through a DIMM socket.

ECC in NON-ECC slots?
Is it ever possible to use ECC DDR in NON-ECC 184-pin DDR slots? Logically, it should work, just ignore the extra bits? Please add details here and in the article.-96.233.20.116 (talk) 19:21, 28 June 2012 (UTC)

SDRAM BUS display
We have lots of talk about RAS & CAS latency, but it is not visibly displayed what happens on the bus in the mean time. When I was on college, we had graphic display of address and data buses, and of control bus timing diagram.

SDRAM in TiTLE?
Maybe just DDR works better. You know... — Preceding unsigned comment added by 23.117.16.45 (talk) 04:25, 20 July 2015 (UTC)
 * No. SDRAM means it is synchronous, and is important. Naki (talk) 22:00, 25 September 2016 (UTC)

POORLY WRITTEN
I have a degree in computer science and have worked in the field for over 30 years. This article swings from technically confusing to just plain poor English. It is next to worthless for any average reader, and very little use to those of us who actually know what the words mean. Please people ... if you're not proficient in English, try to refrain from writing article content. Maybe practice somewhere else first. Poorly written material just confuses and frustrates people, and turns them off to the subject matter. We have few enough folks interested in technology as it is ... we don't need to run anyone off if we can help it. Ugh. — Preceding unsigned comment added by 98.194.39.86 (talk) 02:56, 28 January 2016 (UTC)
 * Yeah, the article is not perfect. So improve it, just go for it. --85.180.130.176 (talk) 09:49, 1 March 2017 (UTC)

Incorrect description of the PC3200 module's organization
Under "Organization" reads:

"""

The individual chips making up a 1 GB memory module are usually organized with 64 Mbits and a data width of 8 bits for each chip, commonly expressed as 64M×8.

"""

64 Mbits above looks incorrect to me: It refers to the configuration of a 512 Mbit chip, which is equivalent to 64M x 8 bits. So IIUC we are talking about 64M locations not bits and the above should read instead something like:

"""

The individual chips making up a 1 GB memory module are usually organized into 64M addressable units each containing 8 bits of data, commonly expressed as 64Mx8.

""" Seipher (talk) 21:17, 1 February 2016 (UTC)

There is the same issue under "High density RAM" at the end of the first paragraph: 128Mbit is just 128M. Seipher (talk) 09:56, 2 February 2016 (UTC) Seipher (talk) 09:56, 2 February 2016 (UTC)

Archive / remove variations?
Variations section is superseded by all other DDR2/ddr3/ddr4 pages, and is outdated. Should the section just offer redirects to DDR2/3/4 pages? — Preceding unsigned comment added by 50.241.94.57 (talk) 18:15, 11 August 2016 (UTC)

Useless Wiki -- maximum size??
Why is maximum size for DDR1/DDR2/DDR3 modules (non-ECC) not clearly listed, esp. in the lists/tables? Someone add this. OR, if all possible sizes are listed, it would be even better. (such as 256 MB/512 MB/etc). Naki (talk) 19:26, 25 September 2016 (UTC)

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Move discussion in progress
There is a move discussion in progress on Talk:Synchronous dynamic random-access memory which affects this page. Please participate on that page and not in this talk page section. Thank you. —RMCD bot 19:15, 14 February 2019 (UTC)

Where are these release years coming from in the table?
I had DDR3 in 2009, but this article says 2011 was the start of the release years. These numbers seem to be absolute nonsense. lukini (talk | contribs) 17:15, 12 January 2022 (UTC)

title: Talk:DDR SDRAM