The Question on Everyone's Mind: Is AM2 Faster?

We've structured this CPU review a little different than in our past, organizing the content into answers to a series of questions that we had about Socket-AM2 and the performance of the platform. The first question on everyone's mind is, of course, is Socket-AM2 any faster than Socket-939. When we previewed AM2 we concluded that no, it wasn't, however we were using pre-release hardware and it was possible that the performance had changed since then. But the following statement from AMD pretty much confirmed exactly what we expected:

"A fair expectation for performance gain from 939-pin to AM2 is about 1% or more across various application-based benchmarks. That assumes equal model numbers for processors and an equal configuration. This also assumes premium memory is used for each configuration."

With AMD telling us that we should expect about a 1% increase in performance, it doesn't look like Socket-AM2 will have much to offer in the way of performance. Of course we needed to confirm for ourselves, and the table below shows just that:

Benchmark - Athlon 64 X2 4800+ Socket-939 (DDR-400) Socket-AM2 (DDR2-800) % Advantage (Socket-AM2)
Cinebench 9.5 Multi-Core Rendering Test 660 658 0%
3dsmax 7 2.79 2.78 0%
Adobe Photoshop CS2 183.2 s 180.2 s +1.6%
DivX 6.1 54 fps 54 fps 0%
WME9 42.2 fps 42.7 fps +1.2%
Quicktime 7.0.4 (H.264) 3.12 min 3.10 min +0.1%
iTunes 6.0.1.4 (MP3) 35 s 35 s 0%
Quake 4 - 10x7 (SMP) 133.1 fps 138.6 fps +4.0%
Oblivion - 10x7 56.1 fps 58.0 fps +3.3%
F.E.A.R. - 10x7 114 fps 116 fps +1.8%
ScienceMark 2.0 (Bandwidth) 5397 MB/s 6844 MB/s +27%
ScienceMark 2.0 (Latency 512-byte stride) 47.3 ns 42.72 ns +9.7%

The numbers we're seeing here today for Socket-939 vs. Socket-AM2 are virtually identical to what we saw last month in our preview. Socket-AM2 doesn't appear to offer any tangible improvement in performance except for within certain games and of course in the memory bandwidth and latency tests. Thankfully, on final hardware, we're at least not seeing any drop in performance.

The good news is that if you've just invested in a new Socket-939 platform, you're not leaving any performance behind by not having an AM2 system. The bad news is that, for AMD, the only performance increases this launch will bring are because of the speed bumps of the Athlon 64 FX-62 and the X2 5000+.

Energy Efficient AM2 CPUs Does AM2 Reduce the Impact of L2 Cache Size?
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  • peternelson - Tuesday, May 23, 2006 - link


    I see no benchmarking in 64 bit mode.

    This is the future, and for maths, Intel's 64 bit was more of a lame copy of AMD 64 bit performance.

    In future this will be increasingly important so even if 32 bit performances are comparable, I'd want to make sure the picture is the same running 64 bit apps.


    Also you summarise "same performance, faster memory, less power". True, but you FORGET one of the main benefits: Pacifica Virtualisation.

    True hardware virtualisation adds to the actual WORK you can keep that processor busy with. It saves time by letting you switch OS instances without rebooting timewasting.

    As it is hardware based VT you should even be able to virtualise an UNMODIFIED OS like Win XP, maybe even Vista!

    So please play with Xen3.

    As you say virtualisation "works" then it is a BIG factor for me in choosing AM2 over 939, (all other things being equal).

    Also the fastest 939 chips have been produced, and AM2 is reaching higher models now.

    So if you want the VERY fastest, it is only available on AM2.

    Don't forget: Not just performance, but performance PER WATT. For these AM2 chips that is similar to 939.

    However, the announcement of 65W EE and EVEN 35W SFF EE!!! are significant compared to the standard 89W

    Intel seem to be positioning Conroe as being "33% better" on performance per watt. However, Conroe isn't even here but when it is, it may not be able to compete with AMD low power offerings.

    Also consider the whole system for conroe vs AMD. Because that AMD power INCLUDES the memory controller, whereas Intel doesn't. The whole motherboard etc may use less power.

    Also in terms of entire system cost, motherboards for AM2 appear to be a bit cheaper than their Intel equivalents, which may offset the current high prices of AMD processors.
    Reply
  • fitten - Wednesday, May 24, 2006 - link

    You should check out the Woodcrest (server targeted Conroe core) previews for power measurements. Performance per Watt, Woodcrest wins (and will be available in 3 weeks)... Absolute power usage under load, Woodcrest wins... and note that the power measurements are for the complete system (video card and HDDs included). (Deep power conservation couldn't be tested on Woodcrest because the parts didn't have it enabled as they were engineering samples.)

    Also, check out the 64bit vs. 32bit comparisons in programs like Cinebench 9.5. Seems Woodcrest 64bit gives a nice boost there (showing that it isn't just a 'lame copy').

    You also seem to forget that Intel already has virtualization extensions out in currently shipping processors (much less Conroe+).

    As far as price, there have been price lists published already. High end Conroe parts are already listed for 1/2 the price of the high end AMD parts... at $500 that gives another $500 for purchase of a motherboard before it touches just the CPU cost of the AMD... I doubt that the motherboards will be that expensive.

    I have 7 AMD machines (four are Athlon64s or X2s) but right now, it looks like my next machine will be a Core2 one. AMD needs to get an answer out... soon. K8L isn't going to cut it. Sure, it'll be good at FPU but the vast majority of work done by CPUs is integer, which are what the majority of improvements are in Core2 (not that they don't have good FPU improvements). So, if you're in a government lab running FPU intensive simulations, K8L may be for you. If you're anyone else, K8L as it has been described looks kind of anemic and not a match for Core2.

    Maybe the real K8L will surprise us, who knows, but it is at least 6 months away (if not longer). By that time, Intel will already be 25% into it's 2-year cycle for the next Core derivative chip (probably farther, time between releases is set to 2-years). AMD looks to be in a bad situation right now... If they have something they're keeping secret, IMO, they need to at least tease us with it. K8L is not a tease, it's only slightly more than a stifled yawn. The longer they go without giving us something to look forward to, the more it looks like they are in major trouble.
    Reply
  • Accord99 - Wednesday, May 24, 2006 - link

    [quote]Don't forget: Not just performance, but performance PER WATT. For these AM2 chips that is similar to 939.

    However, the announcement of 65W EE and EVEN 35W SFF EE!!! are significant compared to the standard 89W

    Intel seem to be positioning Conroe as being "33% better" on performance per watt. However, Conroe isn't even here but when it is, it may not be able to compete with AMD low power offerings. [/quote]
    Given that Woodcrest 3.0GHz has a TDP of 65W, which is borne out by power measurements conducted by Techreport and 2CPU, it's likely that a Conroe that matches the performance of the 35W X2 will at the very least, also match it in power.
    Reply
  • soydios - Tuesday, May 23, 2006 - link

    AMD motherboards are less expensive because they don't have to put in a memory controller.

    AMD processors are more expensive for 2 reasons:
    - integrated memory controller takes up more die space (offset by cheaper motherboard)
    - AMD is still using 90nm on 200mm wafers, while Intel is using 65nm on 300mm wafers (Intel gets more CPUs per wafer bigtime)
    Reply
  • peternelson - Tuesday, May 23, 2006 - link


    Sempron AM2 can do memory up to DDR2-667

    Dualcore AM2 can do memory up to DDR2-800

    However, PLEASE CHECK SINGLE CORE MEMORY SPEED (multiplier issues aside) which you say limited to 667 whereas I got the impression they can also do 800 like dualcores. Correct as necessary.
    Reply
  • smitty3268 - Tuesday, May 23, 2006 - link

    I accidentally hit the "not worth reading" button, so I'm writing this comment to undo it :) Reply
  • fikimiki - Tuesday, May 23, 2006 - link

    There are a couple of reasons for that:
    - K8L photo had a Z-RAM implemented, so they are using this kind of cache for a quite long time.
    - Shared L3 should help Athlon64 in matching Super-Pi and overall performance.
    - Usage of Z-RAM will reduce cache die size by 75% with no architectural changes.

    So FX-64 to beat fastest Core 2 just needs 4MB of cache...
    Easy trick but can be useful to survive till 65nm production...
    Reply
  • Questar - Tuesday, May 23, 2006 - link

    quote:

    K8L photo had a Z-RAM implemented, so they are using this kind of cache for a quite long time.


    It's not going to be Z-RAM. Z-RAM won't even be in K8L.

    “We’ve looked at data from Innovative Silicon and it looks very promising. We still need to assure ourselves that this will work in our own application. We need to see how it scales and we need to make our own test vehicles,”

    Jones, an executive experienced in intellectual property licensing, also declined to comment on AMD’s timetable for introduction of Z-RAM but offered a more general perspective. “In the past it has been two years from when you sign a deal to when it is in production.”


    http://www.eetimes.com/news/latest/showArticle.jht...">http://www.eetimes.com/news/latest/showArticle.jht...
    Reply
  • munky - Tuesday, May 23, 2006 - link

    I think the June trick AMD will pull out is the Clearspeed coprocessor. It definitely won't affect many users, but for those who do invest in the technology, it could provide a decent boost in number crunching power. Reply
  • peternelson - Tuesday, May 23, 2006 - link


    Clearspeed are working on being one acceleration solution, yes, but the already launched acceleration on socket 940 is companies offering plug in Xilinx4 FPGA on hypertransport.

    I hope that gets re-engineered onto socket F pretty quickly. We may see announcements once socket F is actually launched in July.
    Reply

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