AMD AM2: More than just a Memory Change

The new AMD technology refresh, now called AM2, will bring DDR2 memory to the Athlon64 on-processor memory controller. Many in the industry have speculated about the impact of this low latency memory controller on DDR2 performance, which to this point has suffered under the impact of the higher latency Intel Netburst architecture. We are looking forward to the opportunity to take a closer look at DDR2 performance on AM2 - which is everyone's big question.

There will be more than just new memory with AM2, however. We now have details on the new Socket 940 for AM2. It has been widely reported that the new Socket 940 will not be compatible with the existing Socket 940 used for Opteron and early Athlon 64.

Photos of the back of the new AM2 processor show how very close the new design is to the current Socket 940.

AM2 Processor

Current Socket 940 (Reversed)

By flipping the current 940 socket photo and comparing pin-outs to the back of the AM2, you can clearly see the top 2 "lands", areas without pins, are identical in the current Socket 940 and the AM2 Socket 940. However, the bottom two lands are in different locations. The bottom right land is the same 2 pins up, but 7pins form the edge instead of the 5 in the current 940 design. The left land is also in the same row position as the current 940, but it is 6 pins from the left edge instead of 8 as in the current 940 design.

The AM2 940 and current Opteron 940 are so close in design; you have to conclude that AMD could have used the same socket design. But there are numerous electrical differences and different memory is required. AMD apparently used a revised Socket 940 to prevent any possibility that AM2 chips might get accidentally mounted in current Socket 940 motherboards. That is probably a very wise decision.

New AM2 Cage
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  • PrinceGaz - Monday, February 6, 2006 - link

    If you think buying a whole new mobo and processor is worth it for a 10-15% performance increase, then you must be more desperate for CPU performance than most of us. My X2 4400+ even before it was overclocked was more than powerful enough for anything (unless I wanted to shave a few minutes off video transcoding), there seems little point in buying an AM2 socket processor until they transition to 65nm and crank the speed up a bit. Unless you need the virtualisation technology, or would prefer a "secure" computer thanks to the DRM garbage which will be included in AMD chips from the introduction of AM2.

    This article forgot to mention the two real changes with AM2-- virtualisation technology (not really important for most people), and integrated DRM (the first step to someone else controlling your PC).
  • Zebo - Monday, February 6, 2006 - link

    Looks like old HSF will fit to me. The center hooks where CU clips attach on the hold down plates looked like they are in same place in both sockets. All that's changed from my limited no in front of me view is one hold down plate is done with 4 screws to back plate while the other uses two
  • DigitalFreak - Monday, February 6, 2006 - link

    Any info on the new chipsets? Maybe the folks at DailyTech could leak some info that Anandtech can't post... :-)
  • rpsgc - Monday, February 6, 2006 - link

    Look">here :)
  • Orbs - Monday, February 6, 2006 - link

    What about for ATI? Will the RD580 support AM2?
  • Wesley Fink - Monday, February 6, 2006 - link

    The RD580 fully supports AM2.
  • KayKay - Monday, February 6, 2006 - link

    That's really pushing the Q2 2006 target that we'd been hearing about.

    I have seen an AM2 board photo, so I'm hoping we're not that far off,2968.html">,2968.html
  • fzkl - Monday, February 6, 2006 - link

    The HSFs that came with some of the samples AM2's I used for testing were very comfortable to work with. It was a breeze to mount the HSF on the board. This is a move in the right direction though it definitely means more money to upgrade. Anything better = more money. Guess we just have to get used to that funda.
  • BlvdKing - Monday, February 6, 2006 - link

    I was hoping the new socket would be pinless like the Intel LGA 775 socket.
  • DigitalFreak - Monday, February 6, 2006 - link

    I guess I won't be moving my XP-120 cooler over from my P4 system when I upgrade. Thanks AMD!

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