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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  • mino - Friday, December 1, 2006 - link

    If you would bother to read, you would see those IDLE numbers are Without C'n'C.

    Witch C'n'C the IDLE number is be more like 250W than 380W.
  • mino - Sunday, December 3, 2006 - link

    Hell, I should REALLY read after myself more thoroughly...
  • JKing76 - Thursday, November 30, 2006 - link

    What have you got against pickup trucks?
  • Genx87 - Thursday, November 30, 2006 - link

    I think it is safe to say Intel has caught AMD with its pants down this round with their Core 2 Duo line of products. Intels product line is much more compelling and performance\watt is scary good for Intel.

    Hell Intel's offering must be good, it got me to buy their product for the first time in nearly a decade! ;)
  • mino - Friday, December 1, 2006 - link

    Actually not.

    AMD has caught Intel pants down in 2003. It took Intel 3!!! years to come back to game.
    Those 3 yrs Intel was NOT price competitive.

    Intel has just caught up in midle of 2006, this was to be expected and WAS expected by AMD.

    AMD is about to catch up to Intel after 1 year..
    This 1 year AMD IS price competitive, hence it is still in the game..

    The 2008 Intel CSI may catch AMD with pants down. May.

    Actually, in 2008 AMD will have some 30-35% marketshare and be so well entrenched in the corporate market that some mild performance(as now) hiccup is not gonna hurt them in any serious manner.
  • Roy2001 - Thursday, November 30, 2006 - link

    If you need quad-core/CPU system, kentsfield is a much better choice, no question asked.
  • sprockkets - Thursday, November 30, 2006 - link

    Why is it that just putting the other 2 cores on the same package reduces power consumption so much?

    Anyhow, yeah, Intel is ahead, though this would be good for servers, not for desktops. Even so, Intel for now is still better.

    But, I found for perhaps 90% of all people, an old s754 board with a $45 dollar Sempron works fast enough. I wish Anand would check out the new C7 processor mini ITX boards to see how well it works for so little power consumption.
  • Furen - Thursday, November 30, 2006 - link

    The QX6700 pretty much draws twice as much power as the E6700, the big benefit of going for quad-core in a single system is that you only have one motherboard, harddrive, one set of RAM sticks, one video card, etc. The 4x4 is horribly engineered, I think even 400W at load is too much for two Opterons at 3GHz.
  • mino - Friday, December 1, 2006 - link

    Two Opterons DO NOT employ 8000GTX usually ...
    Two Opterons do have 95W TDP(lower voltage) ... compared to 125W for FXs
    Two Opterons are available in 68W TDP ...
    Two Opterons are NOT available in 3GHz flavour ....

    Two Opterons are twice as expensive ....
  • Furen - Thursday, November 30, 2006 - link

    The 4x4 motherboard, that is...

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