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.

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  • DrZoidberg - Monday, April 10, 2006 - link

    Yeah it is disapointing that DDR2 800 doesnt increase performance by much for AMD. I think we will only see nice 20%+ improvements when AMD moves to 65nm CPUS, smaller transistors less power higher clock speed. Too bad 65 nm seems like Quarter 4 at earliest, next year most likely.

    I do hope when Conroe is released AMD does big price cuts, cause their CPUS will no longer have performance crown so they no longer have excuse to have their X2 processors more expensive than Intel, so we should hopefully get X2 4400+ for $300, or X2 3800 for low $200s.
  • Shintai - Monday, April 10, 2006 - link

    Even a 300$ 4400+ would be a bad buy. For 300$ You will get a 2.4Ghz Conroe that will be somewhat like an FX-62. So maybe a 200-250$ 4800+ and a 150-200$ 4400+

    AMD really needs some extremely aggresive pricecuts to be competitive.
  • abhaxus - Tuesday, April 11, 2006 - link

    they don't need to make price cuts yet... when conroe comes out i'm sure they will drop the prices by quite a bit. as it stands, the X2s are by far the best chip on the market and have been for quite some time, and have been reasonably static on price for half a year now. This is the first time in a long time that i remember chips staying THAT static at high prices.

    That said... this review makes me worry for AMD. I hope they have something up their sleeve otherwise this generation will go very badly for them.
  • Sunrise089 - Monday, April 10, 2006 - link

    20% Seriousely?

    I'm no CPU expert, but I cannot imagine that kind of gain. Pentium 4's moving to 65nm and 7900GPUs didnt see anywhere near those kinds of gains.
  • Furen - Monday, April 10, 2006 - link

    I think a 20% clock speed increase is conceivable if a) AMD's 65nm shrink goes off well (let's assume a 10% increase due to this), and b) AMD's embedded germanium technique is 10% better than current DSL silicon. Of course, clocks woul not be 20% better until yields hit a decent point.

    I think that the main way we'll see AMD get closer to a performance parity with Intel will be through the various architectural tweaks in Rev G, though there WILL be some clock speed increase out of manufacturing,.
  • bob661 - Monday, April 10, 2006 - link

    I think I will wait for the die shrink and just get a dual core and some ram for now. I've been trying to decide whether to wait or not to upgrade. I was thinking about waiting for the die shrink anyways.
  • poohbear - Monday, April 10, 2006 - link

    "better late than never" is the expression we all know, not "better early than never". wow, anandtech are really trying to sell this cpu in their "final words" section, even though it seems like a waste your money according to your performance tests. i think i'll stick w/ my s939 and just upgrade to a x2 cpu instead of a whole new socket.:/
  • Brunnis - Monday, April 10, 2006 - link

    You're just reiterating what Anand wrote. He said that there's no point for S939 owners to upgrade, but that AM2 is the natural socket of choice for those who don't already own an up to date system.

    Are you suggesting that those people should buy S939 parts instead, despite them having a very limited future and worse performance? That makes absolutely zero sense.
  • poohbear - Tuesday, April 11, 2006 - link

    nope it makes perfect sense. i wouldnt hold my breath for the am2 is what im saying. im sorry but a 5% increase doesnt justify ditching my s939 and opty 144. and what are u talking about limited life? w/ dualcores available on the s939 they're gonna be around well into 2008. It's 2006 and there are still tons of people using athlon xps and agp, so plz drop your enthusiast perspective on the market, it's not realistic of what the avg person has.
  • sp1nfer - Tuesday, April 11, 2006 - link

    quote:

    w/ dualcores available on the s939 they're gonna be around well into 2008.


    no, it's EOL (end of life) is Q4'06, with socket 754 holding out one year more. By the time you decide to go X2, with AM2 out and all, prices are going to be higher than AM2 counterparts. AMD said it themselves that prices for s939 will be increased near and on AM2 launch. I think Brunnis covered most of it.

    It makes perfect sense.

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