Editing Opteron (section)

===Multi-core Opterons===
[[File:Quad-Core AMD Opteron processor.jpg|thumb|Quad-core "Barcelona" Opteron]]
[[File:AMD Opteron Six Cores.jpg|thumb|Six-core "Istanbul" Opteron]]
In April 2005, AMD introduced its first multi-core Opterons. At the time, AMD's use of the term multi-core in practice meant [[dual-core]]; each physical Opteron chip contained two processor cores. This effectively doubled the computing performance available to each motherboard processor socket. One socket could then deliver the performance of two processors, two sockets could deliver the performance of four processors, and so on. Because motherboard costs increase dramatically as the number of CPU sockets increase, multicore CPUs enable a multiprocessing system to be built at lower cost.

AMD's model number scheme has changed somewhat in light of its new multicore lineup. At the time of its introduction, AMD's fastest multicore Opteron was the model 875, with two cores running at 2.2 [[GHz]] each. AMD's fastest single-core Opteron at this time was the model 252, with one core running at 2.6&nbsp;GHz. For [[Multithreading (computer architecture)|multithreaded]] applications, or many single threaded applications, the model 875 would be much faster than the model 252.

Second-generation Opterons are offered in three series: the 1000 Series (single socket only), the 2000 Series (dual socket-capable), and the 8000 Series (quad or octo socket-capable). The 1000 Series uses the [[Socket AM2|AM2 socket]]. The 2000 Series and 8000 Series use [[Socket F]].[https://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_8796_14309,00.html]

AMD announced its third-generation [[quad-core]] Opteron chips on September 10, 2007<ref>{{Cite news |title= AMD Introduces the World's Most Advanced x86 Processor, Designed for the Demanding Datacenter
|work= Press release |date= September 10, 2007 |publisher= AMD |url= https://www.amd.com/us/press-releases/Pages/Press_Release_119768.aspx |access-date= January 6, 2014 }}</ref><ref>{{Cite web |title= The Inner circuitry of the powerful quad-core AMD processor |publisher= AMD |work= Photo |url= https://www.amd.com/us-en/assets/content_type/Additional/DieImageGallert.swf |url-status= dead |archive-url= https://web.archive.org/web/20081128075230/http://www.amd.com/us-en/assets/content_type/Additional/DieImageGallert.swf |archive-date= November 28, 2008 |access-date= January 6, 2011 }}</ref> 
with hardware vendors announcing servers in the following month. Based on a core design codenamed ''Barcelona'', new power and thermal management techniques were planned for the chips. Earlier dual core DDR2 based platforms were upgradeable to quad core chips.<ref>{{cite web
  | title = Quad-Core Upgradeability
  | url = https://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_8796_14286,00.html
  | access-date = March 6, 2007 }}
6-core Opteron Processors codenamed 'Istanbul' were announced on July 1, 2009. They were a drop-in upgrade for existing Socket F servers.
</ref>
The fourth generation was announced in June 2009 with the ''Istanbul'' hexa-cores. It introduced ''HT&nbsp;Assist'', an additional directory for data location, reducing the overhead for probing and broadcasts. HT&nbsp;Assist uses 1 MB L3 cache per CPU when activated.<ref>{{cite web
  | title = "HT Assist": What is it, and how does it help?
  | url = https://www.amd.com/us/products/server/processors/six-core-opteron/Pages/six-core-faq-ht-assist.aspx
  | access-date = January 2, 2013}}</ref>

In March 2010 AMD released the ''Magny-Cours'' Opteron 6100 series CPUs for [[Socket G34]]. These are 8- and 12-core [[multi-chip module]] CPUs consisting of two four or six-core dies with a [[HyperTransport]] 3.1 link connecting the two dies. These CPUs updated the multi-socket Opteron platform to use DDR3 memory and increased the maximum HyperTransport link speed from 2.40&nbsp;GHz (4.80&nbsp;GT/s) for the ''Istanbul'' CPUs to 3.20&nbsp;GHz (6.40&nbsp;GT/s).

AMD changed the naming scheme for its Opteron models. Opteron 4000 series CPUs on Socket C32 (released July 2010) are dual-socket capable and are targeted at uniprocessor and dual-processor uses. The Opteron 6000 series CPUs on Socket G34 are quad-socket capable and are targeted at high-end dual-processor and quad-processor applications.