Power Consumption

Power consumption of a Quad FX system is simply unreal for a desktop, as it should be because this is effectively a workstation platform with un-buffered memory. At idle our Quad FX test bed consumed nearly 400W, partially because we couldn't get Cool 'n Quiet running on the system, but also because the CPUs and motherboard simply draw an incredible amount of power. Update: We got Cool 'n Quiet working on the motherboard which reduced idle power significantly, down to within a few watts of the Kentsfield system. Load power was unchanged.

CPU Idle Power Load Power Performance per Watt (fps/watt)
AMD Athlon 64 FX-74 (3.0GHz x 4) 217W 456W 17.7
Intel Core 2 Extreme QX6700 (2.66GHz x 4) 213W 263W 32.9

Looking at power consumption under full load, Cool 'n Quiet would have no chance to even make an impact as all cores are being utilized at full speed. Under load the Quad FX system pulled 456W on average, a full 73% more than our Kentsfield testbed.

If we look at performance per watt, the Quad FX loses big time. We specifically chose to look at our WME encoding test because the performance of the FX-74 and QX6700 is pretty close. What you're looking at here is the best case scenario for the Quad FX's performance per watt; in applications where it's significantly slower than Kentsfield the performance per watt will be even worse.

Multitasking Performance Final Words
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  • VooDooAddict - Saturday, December 2, 2006 - link

    It strikes me as odd that you haven't reviewed a Dual Xeon 5300 system.

    While the motherboards aren't geared toward the enthusiast. It would seem anyone who could really benefit from two Dual core Athlon FXs would get incredibly more bang for the $$ out of a Dual Xeon 5300 system giving them 8 cores on an established and sure to be supported platform.

    I only see two major drawbacks to the Dual Xeon as opposed to 4x4.

    You don't have access to SLI. That's unimportant though as people who want SLI would be better served with an Intel QX6700 on an NVIDIA 680i.

    You need FB-DIMMs. Considering the expense you are already at with any Dual CPU system, and the types of activities you'd need to be doing to get real benefit. ECC probably wouldn't be a bad thing to have.

    I'd love to see a review of a Xeon 5300 System with a 8800GTX.
  • yyrkoon - Friday, December 8, 2006 - link

    To the best of my knowledge ECC memory is usually slower compared to non ECC memory. Also, if I didn't read it here, I read it somewhere else, not only is FB-DIMM memory more expensive, it also does not perform as well compared to standard DDR2 memory.

    I think, for now, if you're wanting the best of both PC/server worlds, you would have to settle for a motherboard similar to Asus' Workstation, or Pro line. However, you would still be stuck with a single CPU, with multiple cores, but you would have SLI, PCI-X, and 2-3 PCI 2.3 slots :) As for memory quantity, anything more than 4 GB on a 32 bit OS is a waste (unless you use the right OS with the equivalent of the /PEA boot option, which I understand can cause some system instabilities)
  • yyrkoon - Friday, December 1, 2006 - link

    As far as I can remember, using multiple CPUs (as in socket, not core), has always shown diminishing returns. In fact, I think I remember reading something to that effect here on this web site (or maybe it was TH?). Regardless, having several Dual CPU boxen around, and have had the chance to play around with a few Quad CPU systems, I've seen this with my own two eyes.

    I did not start reading this article with the belief that AMDs solution would beat an Intel quad setup, but I did have hopes that AMDS system would be at least feasible. The way I see it, from these results, AMD should have never even bothered with this design, and would have better spent their time working on future technology.

    A few more mistakes like this, and pretty soon the only choice we're going to have is Intel, and it doesn't matter which company you buy from. We all should be hoping this never happens. My current system right now, is an AM2 system, and I have to say, I'm a bit miffed at AMD for leaving customers like myself out in the cold, when it comes to performance CPUs. So now, since I spent less than $200 for my current Motherboard / CPU, I think I'll Leave AMD in the dust (before they get the chance to do the same to me), and opt for an Intel system board, and CPU, for my next upgrade.
  • stepz - Sunday, December 3, 2006 - link

    quote:

    he way I see it, from these results, AMD should have never even bothered with this design, and would have better spent their time working on future technology.

    To be fair, the engineering effort was close to zero. They sell almost exactly the same stuff as Opterons, only in shinier boxes and surrounded by a lot more nonsense buzzwords. This product is brought to you mainly by the marketing department.
  • fitten - Friday, December 1, 2006 - link

    quote:

    As far as I can remember, using multiple CPUs (as in socket, not core), has always shown diminishing returns.


    Amdahl's Law.
  • T Rush - Thursday, November 30, 2006 - link

    I'm really not that thrilled to see a brand new Intel CPU barely squeak by a similar config from AMD that is using a CPU architecture that is over 4 years old

    I just gave Anand Lal Shimpi's article a closer inspection, we do see an advantage to the new Intel Core2 Q 65nm Kentsfield, but its not as large as I think it should be compared to the AMD64 90nm K8/Hammer dual cores times two...and however the pricing also doesn't reflect the large advantage you would expect to find with a newer more efficient design: as tested the two FX-74's are priced the same as the Extreme QX6700, and then next we see that two FX-72's under pricing the coming Quad Q6600 by a noticeable amount, and last we don't see a Quad Core2 to compete with the two FX-70's at the lowest $599 for the pair...I would expect the newer tech to not only be a much better performer, but also less expensive as well
    ....but to my surprise Shimpi almost caused me to fall out of my chair when I got to the last page and one of his biggest complaints was the higher price of the competition's motherboard!!!!, this to him seems to be a problem for AMD now, but the Intel systems he has tested before he was willing to overlook....here with this comparison he has a problem with the total system cost(mobo+cpus) being higher do to the motherboard being over one third more expensive as tested; $370(which he later even 'rounds up' to $400) for the AMD vs. $260 for the Intel, looking at $110 difference
    ....oddly with even his own widely revered "Tremendous Value Through Overclocking" that he wrote, where the focus is in fact "Value"(not something that I would think is "as big" of an issue when looking at the highest priced/performing/featured/etc. systems that you could possibly buy today) he completely was not bothered by the fact that he was using a $250 motherboard for the "Value" Intel CPUs at as much as $120 difference more to the $130 AMD board he used where value was a factor in that earlier case ..what!!!
  • fitten - Friday, December 1, 2006 - link

    Well... the parts that "barely squeak by" are also running at only 80% of the clock frequency... 2.4GHz Q6600 compared to 3.0GHz AMD FX... and Intel's Core2 architecture seems to have plenty of headroom to go to higher clockspeeds on Intel's whim... 3.6GHz overclocks are pretty common with the Core2Duo parts (and the Quad parts are the same exact cores).

    There's no doubt that the Core2 architecture from Intel is the largest CPU performance bump in a number of years... previous years were almost stagnant as we saw 200MHz to 400MHz clock frequency increases on the same cores as the previous year. Core2 was a performance jump that was similar to the days of the Pentium3 timeframe.
  • T Rush - Thursday, November 30, 2006 - link

    was anyone really expecting AMD's "4X4" system using two CPUs built using the 4 or 5 year old K8/Hammer CPU architecture to out-perform Intel's latest release using its newest recent Core2 architecture?...I would hope not
    ...if anything Intel should have been able to pull off a much larger victory in price and performance....where the only clear major advantage that shows the large difference you would expect to see when comparing very new tech to much older was with the power consumption, which I wouldn't think is that great of concern with any system that is running four cores and most likely dual high end video cards(or more) in a "all out" highest performing/benchmarking gaming desktop system
    the over all win does go to the Intel on this dual dual core battle..but personally I would have liked to of seen a much broader margin before putting all my eggs in one basket as many will do
  • cryptonomicon - Friday, December 1, 2006 - link

    Thats an incredible amount of power... 450w!! Now that's what I need to keep my room warm this winter :D
  • JarredWalton - Friday, December 1, 2006 - link

    You can overclock an E6300 even higher on a lot of P965 boards than on the $225 ASUS P5W DH. The motherboard chosen was used for consistency in benchmarking, not because it is the recommended "budget overclocking" motherboard for socket 775. As for QX6700 barely outperforming FX-74, there's a couple of things to keep in mind. First, you can't buy the AMD chips yet, whereas QX6700 is actually available (albeit a bit expensive). Second, the past indicates that 3.0 GHz is pretty clearly to limit of AMD's current chips on 90 nm.

    Meanwhile you have QX6700 systems shipping factory overclocked at 3.33 GHz and beyond. Sure, with that level of overclocking, the power draw might actually begin to be similar between the two platforms. However, a 25% overclock of a Core 2 Quad certainly isn't going to close the margins. And given that these are indigenous platforms we are talking about, overclocking is going to be far more common than not I would say.

    I'm not sure on Q6600 pricing either (since it's not available), though I've heard at least one rumor suggest the price has dropped to around $500. Guess we'll wait and see there as well. Basically, we are see Core 2 Quad beat AMD's latest and greatest in almost every test, without even pushing the clock speed limits. In seven months, we can evaluate again, and maybe AMD will have the lead.

    Basically, we should expect the margin of victory to be slightly lower with a single socket quad core going up against dual socket dual core then it was with Core 2 Duo going up against Athlon X2. The dual sockets give more memory bandwidth, so particularly when running a NUMA aware operating system, things should be pretty close when comparing FX-74 against QX6700. AMD was basically able to close the performance gap somewhat by throwing more power and hardware at the problem, sort of similar to what Intel did with Pentium D. It wasn't a good solution when Intel did it, and it's not a good solution now. It is "OK" at best.

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