Imitation To Innovation: AMD's Best CPUs

The K6: AMD Extends Its Range

In 1997, AMD released a new processor: the K6. Unlike the K5, which was created by AMD, the K6 was the result of the work done by NexGen on the Nx686. This processor was compatible with Socket 7 (Pentium) motherboards and offered very good performance compared to Intel’s Pentium II processors, at a much lower price. The K6’s FPU was still a little weak compared to Intel’s. A 250 nm version of the K6, called Little Foot, came out in 1998.

Also in 1998, AMD announced the K6-2, a processor that used a faster bus (100 MHz) and had improved SIMD performance. It also had one more MMX unit than the K6 and a new instruction set, 3DNow!, for floating-point calculations (MMX handled only integers). The K6-2 (400 and up) was a big success because it was a good upgrade solution for owners of Pentium MMX platforms—by using the 2X multiplier on a motherboard with a 66 MHz bus, the processor was in fact operating at 6X (400 MHz), which permitted a significant gain in speed at a lower upgrade cost.

Finally, in 1999, AMD released the third version of the K6, the K6-III. The main difference from the K6-2 version was an on-chip 256 KB cache. The K6-III was very fast, but also very costly to produce, and was quickly replaced by the Athlon (K7).

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Code nameK6, Little Foot (250 nm)K6-3D, ChomperSharptooth
Date released1997/199819981999
Data bus64-bits64-bits64-bits
Address bus32-bits32-bits32-bits
Maximum memory4,096 MB4,096 MB4,096 MB
L1 cache32 KB + 32 KB32 + 32 KB32 + 32 KB
L2 cachemotherboard (FSB frequency)motherboard (FSB frequency)256 KB (CPU frequency)
L3 cachenonomotherboard (FSB frequency)
Clock frequency166-300 MHz300-550 MHz400-450 MHz
FSB50-66 MHz66-100 MHz100 MHz
Fabrication process350 - 250 nm250 nm250 nm
Number of transistors8.8 million9.3 million21.3 million
Power consumption12-28 W13-25 W10-17 W
Voltage2.2–2.9 V–3.2 V2.2–2.4 V2.2–2.4 V
Die surface area157-68 mm²81 mm²118 mm²
ConnectorSocket 7Socket 7 / Super Socket 7Super Socket 7

AMD also marketed K6-2+ and K6-3+ processors, mainly for portable PCs. These used a 180 nm fab process and had an on-chip 128 KB (K6-2+) or 256 KB (K6-3+) L2 cache.

  • Ryun
    Nice article, thanks for another trip-down-memory-lane.
  • randomizer
    I swear I had a Clawhammer with 512MB L2 cache.
  • cpuTweaker
    Lackluster article...a lot of backround on the chips were left out, fact that make thier acomplishments truely impressive. To THG's credit, their was at least some mention of the impact Alpha had on some of the chip designs, but no where near being complete.

    Where the intel article seemed to overshadow intel's little victories, this article seems to gloss over AMD innovation (though i'll admit that i didn't recall the bit about the Intel chip, either the pentium or pentium pro, that gave incorrect values for mathmatical equations)

    Both articles really need alot more detail added. As i've actually ranted about the history i'm reffering to in the comments section of the intel article as well as many other's i won't re-hash it.
  • neiroatopelcc
    Despite not being terribly detailed, I still like these recaps. Good articles really, all of them. Now all we need is one on alpha, and on how the mac stuff went before it was called intel
  • neiroatopelcc
    Oh and on ati I suppose, seeing we've already had nvidia :9 ... or even matrox, 3dfx and others that have vanished in a combo article...

    This is like viasat history - only more specific and technical
  • AMD 386 SX @25 MHz was powering my first personal computer. The whole computer costed ~4000$ and it wasn't even top performance.
    AMD 486 @120 Mhz was making my friends that bought an early Pentium red with envy.

  • jj463rd
    I had several systems with the AMD 486 X5 processor at 133 Mhz.I also have 2 K6-2 systems,1 Athlon a Athlon 64 and a Phenom X4 9850 BE system.Actually most of my systems are Intel basedthough.When I first heard that AMD was in pretty big trouble I still wouldn't get a B2 Phenom but when they fixed the bug I decided to help them out by building the Phenom X4 9850BE system which runs very well.Plus I've just ordered some new ATI graphics cards too.
    Someone gave me a AMD K5 system.
    Thanks for the article.
  • Malovane
    Heh, owned one AMD processor of every line, starting with the 8086 and ending with the Phenom. Wasn't even intentional for the first decade, but I'm glad I did. Liked the article, though it could have gone into a bit more detail and back story.
  • Minerva
    I enjoy these articles as well, as I collect old hardware...
    I have quite a few chips from both makers, including the AMD 40MHz 386, and an Intel 386 & 387 33MHz cpu's, which are quite scarce...
  • NightLight
    I too collect old hardware Minerva, in fact, I still have a lot of them still in running order on a mainboard ! Good Review, I just loved to see that windows 3 series again :)Altough a little bit biased...