To say that AMD has been uncharacteristically quiet lately would be an understatement of epic proportions. The company that had been so vocal about their K8 architecture in the past will hardly say anything at all about future products, extending even to its forthcoming AM2 platform. In just two months AMD is scheduled to officially unveil its first DDR2 platform (Socket-AM2), but we've heard virtually nothing about performance expectations.

Back in January we sought to discover for ourselves what AMD's Socket-AM2 platform would have in store for end users. You'll remember that when Intel made the shift to DDR2 it basically yielded no tangible performance improvement, and we were all quite afraid that the same would be true of AM2. When we finally tested the AM2 samples that were available at the time, performance was absolutely dismal. Not only could AMD's AM2 not outperform currently shipping Socket-939 platforms, but due to serious issues with the chip's memory controller performance was significantly lower.

Given that AMD was supposed to launch in June at Computex, the fact that AM2 was performing so poorly just five months before launch was cause for worry. Despite our worries, we elected not to publish benchmark results and to give AMD more time to fix the problems. We're not interested in creating mass panic by testing a product that's clearly premature.

In February we tried once more, this time with a new spin of the AM2 silicon, but performance continued to be lower than Socket-939. Luckily for AMD, the performance had improved significantly, so it was slower than Socket-939 but not as much as before.

The next revision of the AM2 silicon we received sometime in March, and this one finally added support for DDR2-800, which is what AM2 will launch with supposedly at Computex. With the launch only three months out, we expected performance to be at final shipping levels, and we were left disappointed once more. Even with DDR2-800 at the best timings we could manage back then, Socket-AM2 was unable to outperform Socket-939 at DDR-400.

That brings us to today; we're now in the month of April, with less than two months before AMD's official unveiling of its Socket-AM2 platform at Computex in June, and yes we have a brand new spin of AM2 silicon here to test. We should note that it's not all AMD that's been holding AM2 performance behind. The motherboard makers have of course gone through their fair share of board revisions, not to mention the various chipset revisions that have changed performance as well. Regardless, according to internal AMD documents, AM2 CPUs are going to start being sold to distributors starting next month, leaving very little time for significant changes to the CPU to impact performance. We feel that now is as good of a time to preview AM2 performance and put things into perspective as we're likely to get before the official launch.

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  • Anemone - Monday, April 10, 2006 - link

    Don't forget capacity. If you loaded up 4 memory slots to bring 939 machines to 4gb, you harmed timings. DDR2 can bring 2gb on a module at good timings and thus make a higher performance 4gb machine. Why is this important? In Vista (yep I know it's delayed) you will find that gamers and power users of a wide variety will want 4gb machines, much the same as a good number of folks are starting to use 2gb machines now. The larger footprint of Vista ups the ante. It's not that 2gb won't be enough, it will do. Just as 1gb today "will do". But come the end of this year 4gb will start to be that cutting edge amount and that suits the use if DDR2 very well.

    You already mentioned the power issue, with 1.8V for DDR2. That is something AMD needed in the mobile arena to stay competitive, so if they were already designing a top notch DDR2 controller, might as well do the entire cpu line. Since much of the market is actually starting to shift to mobile solutions, from a growth standpoint, being competitive here is going to be telling in each company's numbers. Since Merom is having heat issues (hence why Conroe is coming out so far ahead of Merom, meaning less of a heat budget constraint) you can expect that Turion X2's with DDR2 will put some pain on Yonah machines. I suspect that AMD knows their bandwidth is superb with DDR2 and are designing Turion X2's with 512 cache because it doesn't hurt them much. Watch this area in 2006, because the world won't be painted blue if AMD does well here. Intel is likely well aware and will push as hard as possible to bring Merom out to keep AMD from making ground. Mobile designs under S1 socket are coming aplenty.

    $.02
    Reply
  • coldpower27 - Monday, April 10, 2006 - link


    I must have missed it by what clock rate and what amount of cach were the models used???
    Reply
  • Anand Lal Shimpi - Monday, April 10, 2006 - link

    We purposefully didn't publish this information to protect our source of the CPU.

    Take care,
    Anand
    Reply
  • flyck - Monday, April 10, 2006 - link

    well ofcourse we don't know the clock. But it is an important factor. @ 1.8GHz A64 didn't bennifit from dual channel. but it think @ 2.8GHz that story was totally different. So if you are testing @ 2.4GHz. there could be a larger gap @ 3GHz for example. Reply
  • Anand Lal Shimpi - Monday, April 10, 2006 - link

    Very true, but from what I've seen the picture doesn't change much from the 3800+ up to the FX-62, at least with current CPUs/platforms. The main thing that shows a performance difference is when going to even lower latency memory. You are right though, the hungrier the CPU gets (faster clock, wider core, etc...) the more it depends on a high bandwidth memory bus. However, I do believe that AMD's own model numbers tell the tale of what to expect.

    I think that at the end of the day the 2 - 7% increase range is what will hold, with the vast majority of applications falling at the 2% end of the spectrum.

    Take care,
    Anand
    Reply
  • ozzimark - Monday, April 10, 2006 - link

    though one thing to keep in mind: memory efficiency is directly related to the cpu mhz. i've found that going from 2ghz to 3ghz while keeping the ram at 250mhz increases bandwidth by around 1800mb/s on my s939 rig :eek: Reply
  • Sunrise089 - Monday, April 10, 2006 - link

    I think there will be a lot of current users taking the upgrade path in my subject line, or something close to it. I may very well buy a new AMD chip in 2007, I'd sure like to be able to, but for the next 12 months I only see myself buying a used, overclock proven 2x1meg cache s939 X2 at the end of summer, and then trading up to Conroe during the holidays. I can't really see anyone but the strongest fanboys (and I'm pretty strong) buying AM2. Reply
  • AnnonymousCoward - Monday, April 10, 2006 - link

    Why in the world do you upgrade so often? My path might be AthlonXP 1800+ --> Conroe. Reply
  • 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.
    Reply
  • 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.
    Reply

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