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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  • TrogdorJW - Tuesday, April 11, 2006 - link

    "Facts"? That site is merely an ultra-pro-AMD/ultra-anti-Intel blog factory. It might as well be titled, "The Ravings of a Lunatic Fanboy!" I think just about every article ends up ripping on Intel in some fashion. He's actually still proclaiming the near-future death of Intel, I think. "Intel is dead, and the only reason they haven't realized it is because they don't have a brain." I think that was what he stated on one of the "articles".

    Isn't this the same Sharky that has been talking about the demise of Intel for years, like since the Athlon days? What will he say when Intel ships 2.66 GHz Conroe chips that easily outperform FX-60 chips in meaningful benchmarks at $300 or so, and then follow it up by having 3.0+ GHz parts? I can already guess what he'll say: Intel is just being weak by including more cache, making more chips, selling more processors, yada yada yada.

    Look, Intel isn't great, and AMD isn't the promised Mesiah. Both are mega-corporations looking to make money. End of story. What has AMD really done new in the past three years? They've integrated the memory controller into K7, and they've pushed 64-bits onto us. I still haven't done any 64-bit computing, because for 99% of what I do, it's meaningless. Any benchmark that shows 64-bit computing as substantially faster (like Sharky illustrated on the Conroe article with ScienceMark) has just unveiled itself as a synthetic test that most people will never use. Tasks that can really benefit from 64-bit floats/integers can already be done more efficiently with MMX/SSE/SSE2/SSE3. The only thing 64-bits really adds is the ability to address more than 4GB of RAM, so until we're all running 4GB of RAM it isn't necessary.
  • AnandThenMan - Tuesday, April 11, 2006 - link


    What has AMD really done new in the past three years? They've integrated the memory controller into K7, and they've pushed 64-bits onto us. I still haven't done any 64-bit computing, because for 99% of what I do, it's meaningless.

    You have no idea what you are talking about. Zero. x64 is very, very important and valuable. Just because YOU don't see any benefit is meaningless. So I suppose Vista 64 bit edition is meaningless too. And I suppose x64 in the server space is meaningless, even though smart people are demanding it to the point where AMD can not make the Opteron fast enough. 64 bit applications are going to be EVERYTHING, especially in 4,8,16 and more processor/core settings. Unless for starters, you think 4 gigs of RAM is more than enough moving forward. :nuts: Meaningless indeed.

    AMD has the interconnect infrastructure that will take them into multi-core, mult processor territory that Intel can only DREAM about. Couple that with x64 and Intel seems lost in the wilderness by comparison. What's next from Intel, a 64 meg shared cache?

    Conroe is a short term solution, period. It may put Intel temporarily back in the thick of things. But it does not solve Intel's hopelessly outdated FSB mentality. It does not solve the fact that Intel has no idea how to add x64 to their mobile parts. It does not change the fact that AMD will be further extending x64, forcing Intel to play catch up again. It does not change the fact that Intel's x64 bit hack is actually slower than running in 32 bit mode.

    Sorry, but we have all seen this movie before. Go back and read the Intel hype and press releases from the last 3 years. They are nearly a carbon copy of what is happening now.
  • jjunos - Tuesday, April 11, 2006 - link

    lol fanboi alert.

    If you read his post, he was stating that general users will probably never see a tangible performance improvement from 64bit computing.

    Tho that doesn't account for architectual changes to implement 64bits.
  • NullSubroutine - Monday, April 10, 2006 - link

    reason for changing:

    1) lower power requirements for primarily laptops and servers
    2) changing to ddr2 helps the industry not make two different main memory types
    3) gives more bandwidth for quad cores across entire product line
    4) released before back to school business (time related - gives them enough time to saturate the market with the technology)
  • Calin - Thursday, April 13, 2006 - link

    Unified socket interface - this way, anyone could use the same mainboard with processors from the lowly Semprons (at some $50) to the ultrahigh FX line ($1000). This helps the small shops in the retail channel, as they won't need to stock so many mainboard types (socket related). Reply
  • fikimiki - Monday, April 10, 2006 - link

    You forgetting one fact regarding AM2 platform. It is going to support four-core CPU.
    And using DDR2 AMD will be able to support four memory hungry cores (ups forbidden word).
    The product launch and availability of X4/Opterons will be September I think to be faster than Intel for sure.

    AMD is playing with us, because need best performance processors to stay on top of Intel offer. Why? The capacity is the answer. It is better to sell 1 CPU for 2000$ than 10 for 170$. Q2/Q3 AM2/939 is enough for first wave of Conroes. Then we will see X4 and other fun stuff like K8L to keep Intel and to extend the FAB3x capacity.
  • Shintai - Monday, April 10, 2006 - link

    There is a few errors tho.

    Making 4cores on 90nm is suicide. It would be a massive sized chip, and we would talk of speeds of like 2.0-2.4ghz peak and a massive TDP. I guess a chip like that fastly would cost 2000$+
    So don´t expect a 4 core chip from AMD before 65nm, so sometimes in 2007. The chance of having a 4core chip failing under production right now is massive. Also a 4core chip takes waffer space as said, so again, AMD wont ship many CPUs. So unless you want AMD to be a server vendor only..then no. 4 core AMD chips will start in the highend servers i presume, we talk Socket F here.

    Intel comes with a 4 core (2 DC bolted) in Q1 2007 as a desktop. Later on they will make a "real" 4core chip. But this is the most wise and profitable way to start with, take 2 working dualcores and get a quadcore. Cheap and easy.

    Sure one 2000$ CPu is better than 10 or 20 170$ chips. But they are just killing themselves that way and you wont see them in any desktop anymore then. But maybe thats Hectors plan, all new AMD developments look very serverside.

    Also no 2006 roadmaps for AMD shows quadcores...
  • Calin - Thursday, April 13, 2006 - link

    Even with the FSB interconnect (core to core) in Intel's current Dual Cores, their performance (in real applications) isn't degraded so much. That is, considering their performance in core-to-core data transfers is lower than half of AMD's current dual cores.
    If you can make single cores at 80% rate of success (and 20% failures), then dual cores on a single chip would take some 20% + (1-20%)x20%, or 36% bad, and quad cores would take almost 60% failures. Compare this to two bolted dual cores at 36% failures, and as a result, Intel can produce almost twice as many two chips quad cores than single chip quad cores. Is the performance hit significant? We don't know very well (for quad cores). For dual cores, the performance hit is existant but (right now) not so significant (based on scalability from two to four cores servers between Opteron and Xeons).
  • Thor33 - Monday, April 10, 2006 - link

    It seems the test was done with the fastest memory available in fact is a PC2-8000 1000mhz rated. OCZ EL DDR2 PC2-8000 / 1000 MHz / Platinum XTC / Extreme Edition
    Unless there is a typo on the test memory utilized below is PC8000 drop down to work as PC2-6400?
    PC2-6400 OCZ PC8000 DDR2-800 4-5-4-15 (1GB x 2)
    OCZ DDR-400 2-3-2 (1GB x 2)

    The test should be a PC2-6400 which is DDR2-800 mhz rated memory. If this test is performed with an average memory maker DDR2 PC2-6400 memory the score will be even less impressive. This is worth mentioning.

    Rated at DDR2-1000, this OCZ announces right off the bat that it is serious new memory. Past DDR2 has struggled to reach DDR2-1000, so rating this new OCZ at DDR2-1000 is a "look-at-me" announcement. The rated timings of 4-5-4-15 at DDR2-1000 are also exceptionally fast for DDR2 memory at that speed. By the way, for those of you who have trouble translating PC speed ratings to Memory Speeds, all you have to do is divide by 8. Thus PC2-8000 is DDR2-1000 speed, PC-5400 is DDR2-667 (results are approximate), PC2-6400 is DDR2-800, etc.

  • waldo - Monday, April 10, 2006 - link

    I haven't heard anything about changes in regards to the opteron platform, or are they staying the same. I would assume they would change to use the ddr2 memory as well.

    I actually can't see how purchasing a new AM2 system is good for anyone, whether a new system or upgrading. With prices being higher, almost double, and parts being barely similar in performance with premium boards, memory, etc., it doesn't seem like a good idea for anyone to hop on early to the AM2 platform. Just seems like a waste of a lot of money. In this case, the latest is not the greatest.

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