View source for AMD K6-2

{{short description|CPU by AMD}}
{{more citations needed|date=December 2010}}
{{Infobox CPU
| name        = K6-2
| image       = AMD K6-II Processor Logo.svg
| produced-start = May 28, 1998
| produced-end = End of 2003<ref>[https://www.theregister.co.uk/2001/08/15/amd_to_kill_k6_k6ii/ AMD to kill K6, K6-II, K6-III]</ref>
| slowest     = 200  | slow-unit     = MHz
| fastest     = 570  | fast-unit     = MHz
| fsb-slowest = 66   | fsb-slow-unit = MHz
| fsb-fastest = 100  | fsb-fast-unit = MHz
| manuf1      = [[AMD]]
| core1       = Chomper
| core2       = Chomper Extended
| size-from   = 250 nm
| arch        = 
| microarch   = K6
| predecessor = [[AMD K6|K6]]
| successor   = [[AMD K6-III|K6-III]], [[Duron]]
| sock1       = [[Socket 7]] 
| sock2       = [[Super Socket 7]] 
| numcores    = 1
| l1cache     = 64 KiB
| extensions  =[[MMX (instruction set)|MMX]]|extensions2=[[3DNow!]]|instructions=[[x86]]}}

[[File:AMD K6-2 266 MHz (16498137495).jpg|thumbnail|AMD K6-2 266 MHz]]
The '''K6-2''' is an [[x86]] [[microprocessor]] introduced by [[AMD]] on May 28, 1998,<ref>{{Cite web|title=AMD Introduces AMD-K6-2 Processor with New 3DNow! Technology |publisher=Advanced Micro Devices |date=1998-05-28 |url=https://www.amd.com/us/press-releases/Pages/Press_Release_894.aspx |archiveurl=https://web.archive.org/web/20140202135928/http://www.amd.com/us/press-releases/Pages/Press_Release_894.aspx |archivedate=2014-02-02 |url-status=live }}</ref> and available in speeds ranging from 266 to 550 [[Megahertz|MHz]]. An enhancement of the original K6, the K6-2 introduced AMD's [[3DNow!]] SIMD instruction set and an upgraded system-bus interface called [[Super Socket 7]], which was backward compatible with older [[Socket 7]] [[motherboard]]s. It was manufactured using a 250 nanometer process, ran at 2.2 [[volt]]s, and had 9.3 million [[transistor]]s.

==History==
[[Image:Amdk62 arch.svg|300px|thumb|The AMD K6-2 architecture.]]
[[File:AMD@250nm@K6@Model8(chomper xt) - (cpuid58C)@AMD-K6-2 500AFX@2.2V CORE A 0023BPDW 1998 AMD DSCx8 polysilicon@5x.jpg|thumb|Die shot of an AMD K6-2 500AFX processor]]
The K6-2 was designed as a competitor to [[Intel|Intel's]] flagship processor, the significantly more expensive [[Pentium II]]. Performance of the two chips was similar: the previous K6 tended to be faster for general-purpose computing, while the Intel part was faster in x87 floating-point applications. To battle the Pentium II's dominance on floating point calculations the K6-2 was the first CPU to introduce a floating point [[SIMD]] instruction set (dubbed [[3DNow!]] by AMD), which significantly boosted performance. However programs needed to be specifically tailored for the new instructions and despite beating Intel's [[Streaming SIMD Extensions|SSE]] instruction set to market, 3DNow achieved only limited popularity.

Super Socket 7, which increased the processor bus from 66&nbsp;MHz to 100&nbsp;MHz, allowed the K6-2 to withstand the effects of ever-increasing CPU multipliers fairly gracefully and in later life it remained surprisingly competitive. Nearly all K6-2s were designed to use 100&nbsp;MHz [[Super Socket 7]] mainboards, allowing the system-bus to keep pace with the K6-2's clock-frequency.

The K6-2 was a very financially successful chip and enabled AMD to earn the revenue it would need to introduce the forthcoming [[Athlon]].  The introductory K6-2 300 was by far the best-selling variant. It rapidly established an excellent reputation in the marketplace and offered a favorable price/performance ratio versus Intel's [[Celeron]] 300A. While the K6-2 had mediocre floating-point performance compared to the Celeron, it offered faster system RAM access (courtesy of the Super 7 mainboard), as well as 3DNow graphics extensions.

As the market moved on, AMD released a long series of faster K6-2 parts, the best-selling ones being the 350, 400, 450, and 500. By the time the 450 and the 500 were mainstream parts, the K6-2 family had already moved to the budget PC segment, where it still competed successfully against Intel's Celeron.

==K6-2+==
Despite the name, the little-known K6-2+ was based on the AMD K6-III+ design (model 13) with 128&nbsp;KiB of integrated [[L2 cache]] and built on a 0.18 [[micrometre]] process (essentially a [[AMD K6-III#K6-III+ and K6-2+|K6-III+]] with half the L2 cache). The K6-2+ was specifically designed as a low-power mobile CPU. Some motherboard companies such as Gigabyte and FIC provided BIOS updates for their desktop motherboards to allow for usage of these processors; for other officially not supported mainboards, the community created [[Unofficial patch|unofficial BIOS updates]] on their own.<ref>{{cite web |url=http://www.ryston.cz/petr/bios/ |title=Award BIOS Modifications |last1=Soucek |first1=Petr |date=2002-07-07 |access-date=2017-07-19 |archive-date=2020-07-16 |archive-url=https://web.archive.org/web/20200716224049/http://www.ryston.cz/petr/bios/ |url-status=dead }}</ref><ref>{{cite web |url=http://web.inter.nl.net/hcc/J.Steunebrink/k6plus.htm |title=The Unofficial AMD K6-2+ / K6-III+ Page |last1=Steunebrink |first1=Jan |date=2008-07-02 |access-date=2017-07-19 |archive-date=2021-02-11 |archive-url=https://web.archive.org/web/20210211064357/http://web.inter.nl.net/hcc/J.Steunebrink/k6plus.htm |url-status=dead }}</ref>

Most K6-2+ motherboards did not support a clock multiplier setting greater than 5.5 since 550&nbsp;MHz was the highest official speed of the K6-2+ (100*5.5 = 550) but a little known feature of both the K6-2 and K6-2+ was that it interpreted the motherboard clock multiplier setting 2 as 6. This allowed many users to run their K6-2+ 550&nbsp;MHz and often even a K6-2+ 500&nbsp;MHz at a speed of 600&nbsp;MHz simply by setting the motherboard clock multiplier to 2.<ref>{{cite web |url=http://www.tomshardware.co.uk/600-mhz-with-socket-7,review-205-4.html |title=600 MHz with Socket 7: The AMD K6-2+ |last1=Völkel |first1=Frank |website=[[Tom's Hardware]] |date=2000-07-13 |access-date=2017-07-19 |archive-date=2018-06-17 |archive-url=https://web.archive.org/web/20180617043321/https://www.tomshardware.co.uk/600-mhz-with-socket-7,review-205-4.html |url-status=dead }}</ref>

== Features  ==
{{empty section|date=March 2023}}

==Models==

===K6-2 (Chomper, 250 nm)===
[[Image:AMD-K6-2 350AMZ.jpg|thumb|AMD K6-2 Microprocessor]]
[[Image:KL AMD K6-2 Chomper-XT.jpg|right|thumb|180px|AMD K6-2, ''Chomper-XT''.]]
[[Image:K6-2Bare.jpg|right|thumb|AMD-K6-2 with integrated heat spreader removed]]
* Package number: 26050
* [[CPUID]]: Family 5, Model 8, Stepping 0
* L1-Cache: 32 + 32 KiB (Data + Instructions)
* [[MMX (instruction set)|MMX]], [[3DNow!]]
* 9.3 million transistors
* [[Super Socket 7]]
* [[Front-side bus]]: 66, 100&nbsp;MHz
* VCore: 2.2V
* First release: May 28, 1998
* Manufacturing process: 250&nbsp;nm
* Clockrate: 233, 266, 300, 333, 350 & 366&nbsp;MHz

===K6-2 (Chomper Extended (CXT), 250 nm)===
* Package number: 26351
* CPUID: Family 5, Model 8, Stepping 12
* L1-Cache: 32 + 32 KiB (Data + Instructions)
* [[MMX (instruction set)|MMX]], [[3DNow!]]
* [[Super Socket 7]]
* [[Front-side bus]]: 66, 95, 97, 100&nbsp;MHz
* VCore: 2.0(mobile)/2.2/2.3/2.4V
* First release: November 16, 1998
* Manufacturing process: 250&nbsp;nm
* Clockrate: 200, 233, 266, 300, 333, 350, 366, 380, 400, 427.5, 450, 475, 500, 533 & 550&nbsp;MHz

==References==
{{reflist|30em}}

==Further reading==
* Khanna, R. et al. (1998). "A 0.25μm x86 microprocessor with a 100MHz Socket 7 interface". ''ISSCC Digest of Technical Papers'', pp.&nbsp;242&ndash;243.

==External links==
{{Commons category}}
{{more footnotes needed|date=January 2012}}
* [https://web.archive.org/web/20080224173116/http://www.amd.com/us-en/Processors/ProductInformation/0%2C%2C30_118_1260_1262%2C00.html AMD-K6-2 Processor] AMD (archived version)
* [https://web.archive.org/web/20040929112209/http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=1406 Anandtech: Super7 Upgrade Guide]
* [https://web.archive.org/web/20031009032008/http://www.geek.com/procspec/amd/k63dmmx.htm Geek.com: AMD-K6-2 (K6 3D MMX)]
*  at Geek.com
* [http://www.pcguide.com/ref/cpu/fam/g6.htm Technical overview of the AMD-K6 series]
* [http://www.cpushack.com/gallery/index.php?folder=/chippics/AMD/K6-2/ Pictures of AMD-K6-2 chips at CPUShack.com] {{Webarchive|url=https://web.archive.org/web/20191208213115/http://www.cpushack.com/gallery/index.php?folder=%2Fchippics%2FAMD%2FK6-2%2F |date=2019-12-08 }}

{{AMD processors}}

[[Category:Computer-related introductions in 1998]]
[[Category:AMD x86 microprocessors|K06-2]]
[[Category:Superscalar microprocessors]]