AM2 in Detail

Of course the most prominent feature of AMD's Socket-AM2 platform is the new socket and its support for DDR2 memory.  As we've already mentioned, Socket-AM2 is a 940-pin socket that is keyed differently from the original 940-pin Athlon 64/Opteron sockets; only AM2 processors will physically fit into an AM2 motherboard. 


Socket-939 (left) vs. Socket-AM2 (right)

Socket-939
Socket-AM2

 

One of the Athlon 64's strongest selling points continues to be its on-die memory controller, which has of course been significantly changed for the new Socket-AM2 platform.  All AM2 CPUs feature a 128-bit wide DDR2 memory controller, compared to the 128-bit DDR memory controller that we've come to know from the Socket-939 platform.  A DDR2 memory interface actually requires more pins than a DDR1 interface, but AMD was able to keep the AM2 pin count down by removing a large number of unnecessary pins on the Athlon 64's package.  When the Socket-940/939 Athlon 64s were first designed, approximately 10% of their pins were redundant and could be removed in later designs.  Not desiring to introduce a new socket as frequently as its competition had, AMD waited until Socket-AM2 to remove those unnecessary pins thus enabling a dual-channel DDR2 interface in virtually the same pin count as the earlier DDR1 equipped CPUs. 

All of the Socket-AM2 CPUs support up to DDR2-667, but the AM2 Athlon 64 X2 and Athlon 64 FX models support up to DDR2-800.  Since Socket-AM2 unifies AMD's desktop socket strategy, all Semprons, Athlon 64s, X2s and FX processors will feature this dual channel DDR2 memory controller. 


Corsair partnered with AMD and NVIDIA for the Socket-AM2 and nForce 500 review kits

The lineup of Socket-AM2 processors being introduced today are in the table below:

 CPU Clock Speed  L2 Cache Size  TDP Price
AMD Athlon 64 FX-62 2.8GHz 1MBx2 125W $1031
AMD Athlon 64 X2 5000+ 2.6GHz 512KBx2 89W $696
AMD Athlon 64 X2 4800+ 2.4GHz 1MBx2 89W $645
AMD Athlon 64 X2 4600+ 2.4GHz 512KBx2 89W $558
AMD Athlon 64 X2 4400+ 2.2GHz 1MBx2 89W $470
AMD Athlon 64 X2 4200+ 2.2GHz 512KBx2 89W $365
AMD Athlon 64 X2 4000+ 2.0GHz 1MBx2 89W $328
AMD Athlon 64 X2 3800+ 2.0GHz 512KBx2 89W $303
AMD Athlon 64 3800+ 2.4GHz 512KB 62W $290
AMD Athlon 64 3500+ 2.2GHz 512KB 62W $189
AMD Sempron 3600+ 2.0GHz 256KB 62W $123
AMD Sempron 3500+ 2.0GHz 128KB 62W $109
AMD Sempron 3400+ 1.8GHz 256KB 62W $97
AMD Sempron 3200+ 1.8GHz 128KB 62W $87
AMD Sempron 3000+ 1.6GHz 256KB 62W $77

 

There's basically no price premium for the new Socket-AM2 chips, encouraging a quick transition to AMD's new DDR2 platform.

You will also notice that none of the model numbers have changed, so an Athlon 64 X2 4800+ on Socket-AM2 has the same clock speed and L2 cache size as the Socket-939 version.  Since AMD's model numbers haven't changed, you already know not to expect any major changes in performance with Socket-AM2.  In fact, the only difference on the CPU side is the introduction of the new Athlon 64 FX-62, Athlon 64 X2 5000+ and Athlon 64 X2 4000+.

Index The New Heatsink Tray
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  • mino - Tuesday, May 23, 2006 - link

    2 options:
    1) Quad-core K8 (on 65nm)
    2) High-speed 65nm DC's(improbable)

    BTW what I understand FX-64 is on the way in a few months(july-august). Seems rev. F cores could handle 3.0, just 125W TDP may be the issue.
  • peternelson - Tuesday, May 23, 2006 - link


    Well, I don't think it's a QUAD CORE K8 (aka "Deerhound") because that is not due until late 2007.

    And dualcore K8L is not until 1H/2007.

    We need to choose something happening THIS year.
  • mino - Wednesday, May 24, 2006 - link

    Actually AMD can made Quad-core CPU's even on 90nm if they need to. The core will be huge, yields poor but IMHO 2.2G Quad at 90nm is possible within 125W TDP.

    Also AFAIK AMD has delayed 65nm at least for a quarter intentionally since what they need now is capacity on 90nm. They could not afford any (even short-term) production reduction at this moment. Provided in 3Q/06 FAB 36 is up and running at 10k starts the could afford to dedicate some of them for some high-end opterons and FX's.
  • Furen - Wednesday, May 24, 2006 - link

    http://img.clubic.com/photo/00119525.jpg">http://img.clubic.com/photo/00119525.jpg

    Look at that and tell me how you can possibly fit twice that (90nm dual-core) in one package. Dual-core CPUs are huge to begin with, doubling the number of cores would probably require a pretty big drop in L2 sizes (think 256KB per core...). AMD still is production limited and designing a quad-core chip without going to 65nm would pretty much doom it to being a VERY low-volume part. Heck, Intel's Conroe is huge as well, it's just on a smaller process (the 160sq. mm die size would correspond to something like 300+sq. mm on the 90nm process).
  • jones377 - Tuesday, May 23, 2006 - link

    It's called Socket F
  • Griswold - Tuesday, May 23, 2006 - link

    I dont think so. Socket F isnt really a "secret" nor a stopgap solution.
  • peternelson - Tuesday, May 23, 2006 - link

    I think we hear more about socket F in June and it launches July.

    But that's not what this is alluding to.

    There was an announcement of a roadmap change from Q1/2007 to DECEMBER 2006.

    If I remember right it was two AM2 processors on 65 nanometre process.
  • jones377 - Tuesday, May 23, 2006 - link

    Perhaps not, but it's coming out at around that timeframe. Anything else and we would have gotten wind of it long ago.
  • mlittl3 - Tuesday, May 23, 2006 - link

    A couple of things before I give my guess about the stopgap solution...

    1) K8L as state above WILL HAVE microarchitectural improvements. This has been all over the internet.

    2) AMD's processor pricing page states that the X2 5000+ and FX-62 will be available for both 939 and AM2. I don't know if they messed up but if not, it looks like 939 users can upgrade yet again.

    Okay, here's my guess for the stopgap solution...drum roll...L3 cache. I think AMD will release a 2.8 revised FX-62 with L3 cache or an ahead of schedule 3.0 GHz FX-64 with L3 cache. Just my guess.
  • AllYourBaseAreBelong2Us - Tuesday, May 23, 2006 - link

    The stopgap solution is the 65nm process that will allow AMD to ramp up the speed a bit more and get better TDP ratings.

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