AMD's Quad FX: Technically Quad Core
by Anand Lal Shimpi on November 30, 2006 1:16 PM EST- Posted in
- CPUs
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.
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JarredWalton - Thursday, November 30, 2006 - link
Why is it that just putting the other 2 cores on the same package reduces power consumption so much?It doesn't. Core 2 Duo uses less power than Athlon FX-62, so two of them are going to use less than two FX-62 (or whatever) chips. Now, adding the second socket also adds additional voltage regulation circuitry, so the second socket will increase the power load, but I don't think the second socket accounts for more than a 20W power increase, and probably more like 10W.
Slaimus - Thursday, November 30, 2006 - link
The odd thing for this platform is that the single CPU is actually really cheap versus comparable products. If only server boards can take these CPUs.Beachboy - Thursday, November 30, 2006 - link
I wonder how many diehard AMD enthusiats will want to split a set of these "quads".mino - Friday, December 1, 2006 - link
Count me in!IMHO enthusiast forums are will be full of guys sharing the CPU purchase... :)
peternelson - Friday, December 1, 2006 - link
Very likely eg I would and thought of that, knowing the guys on forums I frequent ;-)The other option is just buy two motherboard/systems and put each of the paired cpus into each one.
rqle - Thursday, November 30, 2006 - link
Best case scenario.100% price reduction in mainboard
Assume these FX cpu perform as well as QCore
Price it Similar to Performance
Major Power Reduction
Assume it a windows error =/ , no clue why you would run server software and e-commerce over softwares/games on this platform
I still have a very hard time recommended this setup to an enthusiast. Already have a hard time reaching 3.0ghz, it going to have a very hard time going just 10% beyond that. The upper limit of AMD cpu doesn’t impress me right now. Cheapo Intel Core 2, with an overclocker in mind seem to have more potential.
photoguy99 - Thursday, November 30, 2006 - link
I generally agree with your logic -But even your best case scenario is impossible because two 90 process CPUs have never come close to the power comsumption of a single 65 process CPU at the same performance.
mino - Friday, December 1, 2006 - link
Depends. EE X2's are more efficient than C2D's. Even performance wise.Not even comparing IDLE C'n'Q and EIST enabled ....
Anonymous Freak - Thursday, November 30, 2006 - link
Of course they'll sell more FX processors now than before. There was literally nothing to differentiate them before, other than clock speed. That, plus now they'll sell two for every computer built with them.But, I have a feeling that the FX processors are going to be even more niche than they were before. Before, it was at least a high end normal processor. Someone could buy a midrange system, and upgrade to an FX later. Now, you have to decide up front that you're going to pay a fortune for the computer. Presently, I have an el-cheapo $99 motherboard that I put my old Pentium 4 in. If I want, I can slap a Quad-Core Core 2 Extreme in there. I can't do that with AMD's setup.
I'm not an Intel fanboy, either. The only reason I even have the Pentium 4 is because a friend gave it to me free when he upgraded his system. I was perfectly happy with my laptop and my AthlonXP 1700+. But a free 3.8 GHz processor is a free 3.8 GHz processor. I went and bought the cheapest motherboard and memory I could find. Spent about $200, and I can upgrade to quad core anytime I want. (Although I'll probably upgrade from the onboard video to a decent PCI-E card first.)
photoguy99 - Thursday, November 30, 2006 - link
I don't know man, why would they sell any more?
To sell more someone would have to buy this "Ford Excursion" of a system. But who is going to buy this?
What boutique shop is going to even sell it?
Is there one single person here who is planning to get one?