Does AM2's Performance Make Sense?

Assuming for a moment that the performance we're seeing here today is representative of what AMD will show off in 2 months, does it make sense? AMD has effectively doubled their memory bandwidth but they've seen virtually no increase in performance, other than in some very isolated situations.

If you'll remember back to the introduction of AMD's Revision E core, we did an article about how the new core brought support four new memory dividers allowing you to run at speeds up to DDR500 without overclocking your CPU or the rest of your system. In that article we looked at the overall performance benefit of DDR-500 over DDR-400 on a Socket-939 platform in a variety of situations. A recap of our performance results is below:

Benchmark Socket-939 (DDR-400) Socket-939 (DDR-480) % Advantage (DDR-480)
Multimedia Winstone 2004 41.9 42.7 2%
3dsmax 6 2.78 2.80 1%
DivX 6.0 50.6 fps 53.2 fps 5%
WME9 4.22 fps 4.28 fps 1%
Quake 3 (10x7) 121.9 fps 127.2 fps 4%
ScienceMark 2.0 (Bandwidth)* 5378 MB/s 5851 MB/s 9%
Note that ScienceMark bandwidth is slightly higher than on the previous page because we used a faster CPU; ScienceMark does vary a bit with CPU speed.

As you can see, given almost a 9% increase in memory bandwidth, we saw similarly small increases in overall performance. It would seem that the Athlon 64, at its current clock speeds, just simply isn't starved enough for memory bandwidth to benefit from an increase in bandwidth. You'll also see that the areas where faster DDR memory helped back then are pretty much the areas where DDR2-800 is showing gains today.

Based on our results from back then, if a 9% increase in memory bandwidth doesn't increase performance tremendously, then the 35% increase in bandwidth we see with DDR2-800 on AM2 shouldn't yield any more of a performance increase. Or simply put, yes, our AM2 performance numbers make sense.

Socket-AM2 Performance Preview Final Words
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  • Shintai - Tuesday, April 11, 2006 - link

    I love how that site only compared Conroes worst results, also the Conroe used crappy memory timings, DDR2-533, preproduction boards, ES sample CPU. Oh, and did we forget its a 300$ CPU vs a 1200$ AMD CPU? Ye we might have forgotten than...didn´t we. Reply
  • mino - Tuesday, April 11, 2006 - link

    Most important it's NON-EXISTENT vs. $1200 CPU.

    Seems many people forget about it.
    Reply
  • 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.
    Reply
  • AnandThenMan - Tuesday, April 11, 2006 - link

    quote:

    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.
    Reply
  • 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.
    Reply
  • 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)
    Reply
  • 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.
    Reply
  • 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...
    Reply
  • 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).
    Reply

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