What's AM2?

As we've mentioned before, AMD's Socket-AM2 is a brand new 940-pin socket that will add DDR2 support for all desktop AMD processors. There will be AM2 versions of Athlon 64, Athlon 64 X2 and Sempron CPUs. All of these are internally known as the Rev F core. When AM2 launches in June, AMD will offer official support for DDR2-533, 667 and 800. As of today, the fastest DDR2 that Intel officially supports is DDR2-667; however, by the time Conroe launches in Q3, Intel will also add DDR2-800 to the list.

What this means is that if you're planning to build a new system later this year - whether it is AMD or Intel based - then you'll be in the market for DDR2 memory. AMD has effectively kept regular DDR-400 quite alive and actually created a market for even faster DDR1 memories with their Athlon 64, but after June that's all going to change. With a single memory standard to support both players in the desktop market, things are going to get a lot simpler. It will also mean that we'll start to see more focus from memory vendors on DDR2, including cheaper variants as well as even lower latency offerings. We'll address whether nor not DDR2-800 is actually needed shortly, but like it or not, if you want a solid upgrade path for the future you'll be looking at investing in some DDR2 memory regardless of whether you choose AMD or Intel.

Alongside DDR2 support, the new Socket-AM2 CPUs add support for AMD's Pacifica Virtualization technology - AMD's answer to Intel's VT. While the two technologies aren't directly compatible, given the respect that AMD has gained over the past few years you can expect software developers to support it. Virtualization will become increasingly more important as time goes on, as we have already seen in recent announcements of Intel VT support on Apple platforms.

The third thing that AM2 brings us is what AMD is calling their Energy Efficient microprocessors. Certain SKUs of AM2 processors will be binned according to their power consumption and grouped into two categories: 65W and 35W. Both TDPs, interestingly enough, are competitive with what Intel is targeting for their 65nm Conroe processors. What's even more impressive is that there will be an Athlon 64 X2 3800+ that's available at both 65W and 35W TDPs, compared to the standard 89W TDP. The chart below will give you an idea of what the new dual core AM2 CPUs are:

CPU Clock Speed L2 Cache Size TDP Options
AMD Athlon 64 FX-62 2.8GHz 1MBx2 125W
AMD Athlon 64 FX-60 2.6GHz 1MBx2 125W
AMD Athlon 64 X2 5000+ 2.6GHz 512KBx2 89W
AMD Athlon 64 X2 4800+ 2.4GHz 1MBx2 89W or 65W
AMD Athlon 64 X2 4600+ 2.4GHz 512KBx2 89W or 65W
AMD Athlon 64 X2 4400+ 2.2GHz 1MBx2 89W or 65W
AMD Athlon 64 X2 4200+ 2.2GHz 512KBx2 89W or 65W
AMD Athlon 64 X2 4000+ 2.0GHz 1MBx2 89W or 65W
AMD Athlon 64 X2 3800+ 2.0GHz 512KBx2 89W or 65W or 35W

In the future you can also expect an FX-64 along with 5200+ and 5400+, but the chart above is what will be launching in the near future (the exception being that the 65W 4800+ that will launch in Q3).

There will also be single core Athlon 64 and Sempron AM2 processors, but we're still waiting for their confirmed specs. Given the specs of the Athlon 64 X2s, you can expect the AM2 Athlon 64s and Semprons to be identical to their Socket-939 counterparts. We'll also finally get retail availability of faster Sempron parts - current socket-939 Semprons are only available with OEM systems.

AMD has already indicated that it will not brand the 65W and 35W parts any differently than the normal 89W Athlon 64 X2s; they will simply have a different part number and carry some sort of lower TDP designation on their box. Of course, they will almost certainly carry a price premium, so that at least should help to differentiate the models somewhat.

As far as major architectural changes go, we haven't been able to find any surprises in any of our AM2 samples. L1 and L2 cache latencies remain unchanged from their Socket-939 counterparts.

You will also notice that AM2 and Socket-939 CPUs appear to carry the same model numbers, meaning that an AM2 X2 4800+ runs at the same speed and has the same cache size as a Socket-939 X2 4800+. Either AMD is being very conservative with its model numbers or we shouldn't expect to see any major clock-for-clock increase in performance with AM2 processors.

Index The Test


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  • Shintai - Monday, April 10, 2006 - link

    If your logic applies, then he wont know anything about Conroe until he got it at home and working. So get over it, even the ES samples out in the wild kicks AMD so hard. The only question was if AM2 would bring extra performance to compete against Conroe, and it surely didn´t. Conroe prices also leaves AMD in the utter dust along with performance. 300$ Conroe E6600 chip or a 1200$ FX62? And the E6600 will be faster in most situations. You gotta be some extreme hardcore fanboi not to go Conroe. Reply
  • bob661 - Monday, April 10, 2006 - link


    So get over it,
    There's nothing to get over, asswipe. You nor he knows for sure how Conroe performs, period! You can fanboi me all you want. Facts are facts. When they ship and there are 3rd party benchmarks on 3rd party machines tested, then we'll all know for sure how they'll perform. Puff, puff, pass man, puff, puff pass.
  • Shintai - Monday, April 10, 2006 - link


    Now cry me a river again and keep whining over something new.
  • AnnonymousCoward - Monday, April 10, 2006 - link

    That's the crappiest website ever! I think a modem is hosting it. Plus it's retarded how the pictures shrink after they're loaded. Reply
  • Furen - Monday, April 10, 2006 - link

    I wouldn't compare the pricing quite yet. AMD's AM2 pricing is for May 5th while Conroe's is for launch day... whenever that happens (and before you say June/July, Intel itself said that it would launch as close to the beginning of Q3 as possible but did not commit to an early Q3 launch).

    Another thing, I have yet to see an E6600 being tested in "most situations", so until I see so, I'll say that your assumption that this is true is a bit irresponsible and fanboyish. Especially so if you consider that neither of the two CPUs (AM2 K8s and Conroes) can be bought quite yet, so convincing someone that one is a better deal is a bit premature. Personally, I think that AMD is going to get its ass handed to it by Conroe but I wouldn't go our of my way to swear it.
  • redbone75 - Monday, April 10, 2006 - link

    Wow. Only twenty posts until someone put up something about Conroe performance. In case you haven't been reading AM2 news or even read the article, AM2 is supposed to launch in June and here we are in April with a preview that, for the most part, is pretty disappointing for anyone that had high hopes for a Conroe challenger. This is just like when Intel migrated to DDR2: it wasn't really necessary but it will give AMD experience for when they can really use it. However, I'm thinking it won't take AMD as long to see more noticeable performance gains with DDR2 than Intel. Regarding Conroe, any way you call it the chip is going to kick some serious @$$, especially if Intel doesn't have any problems ramping up the clock speed. Also, Conroe is still several months away, so unlike AMD, Intel still has some time to tweak the chip for even more performance for its scheduled launch time (won't say date because there is none yet), so who is to say that the current performance claims are bogus. Even if they are now, which I seriously doubt, there just might be enough time for Intel to live up to the hype anyway. Reply
  • MrKaz - Monday, April 10, 2006 - link

    I'm not sure,
    but I think anandtech tested it at 533Mhz again, or
    the processor is locked at 533Mhz.

    Why did anandtech do the test only at 800Mhz?
    Why didn’t test 533Mhz and 667Mhz DDR2 modules?

    Because looking at those numbers:
    -DDR2 533 will achive less bandwidth than DDR400?
    -The latency of DDR2 is lower than DDR1?!?!
    -Is the processor already full, so doesn’t need more bandwidth, and only at (theorical) 4GHz and beyond will use it?
  • defter - Monday, April 10, 2006 - link


    The latency of DDR2 is lower than DDR1?!?!

    At higher speeds yes. Of course 3-4-3 @ 400MHz (DDR2-800) will offer lower latency than 2-2-2 @ 200MHz (DDR1-400).
  • Calin - Monday, April 10, 2006 - link

    DDR2-800 at 4-4-4 should be equivalent to DDR-400 at 2-2-2. Also, DDR2-800 at 6-6-6 would be the same (latency-wise) as DDR-400 at 3-3-3. Reply
  • Furen - Monday, April 10, 2006 - link

    Not quite, DDR2-800 at 4-4-4 is the equivalent of DDR-400 at 4-4-4 because the memory cells run at 200MHz on both modules. Like I said above, though, module latency is not the only factor affecting the total latency, so perhaps DDR2 memory controllers help mitigate this huge latency hit. One of the main reasons why DRAM manufacturers love DDR2 is because their yields are much higher than they are on higher-clocked, aggresively-timed DDR1 due to the higher prefetch (lower operating clock) and the looser timings. Reply

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