July 17th, 2006
Who to believe on power consumption? AMD or Intel?
AMD is on a full marketing counter offensive after the unanimous praise heaped upon Intel's new Core2 "Conroe" desktop processor and are claiming that Intel's low-power ratings are based on a skewed metric. AMD's reasoning is that AMD's TDP (Thermal Design Power) rating is based on maximum power draw while Intel's power rating is based more on typical power consumption and therefore exaggerated. Furthermore, AMD argues that we must look at the whole picture by measuring the power consumed on the entire computer. In fact at last month's press conference at AMD's headquarters, everyone was given a power meter to take home to measure power at the wall. But does AMD's argument have any merit? TomsHardware seems to have the answer when they measured power consumption of identical systems with the exception of AMD or Intel motherboards and CPUs.
Intel rates their new C2D Extreme x6800 processor at 75 watt TDP while AMD rates their new Athlon 64 FX-62 Extreme processor at 125 watt TDP which has a theoretical difference of 50 watts. Since Intel uses an external memory controller on the motherboard, that theoretically translates in to an additional 20 watts of maximum power used by Intel based motherboards so the power advantage should be much smaller than 50 watts if we are to believe AMD. Here are the actual system level measurements from TomsHardware:
* Represents power save idle mode
If we are to believe AMD's claims that Intel uses dubious TDP numbers and has more power hungry chipsets on the motherboard, then we should be seeing a difference far lower than 50 watts and perhaps even a wash. But looking at the highlighted figures, AMD's overall power consumption was actually 66 watts higher than Intel! This (based on TomsHardware numbers) would seem to indicate that not only is Intel NOT over exaggerating their power efficiency numbers, but they're actually being more conservative than AMD. I threw in an overclocked Intel X6800 at a blazing 3.46 GHz for good measure and even that uses 51 watts less power than the AMD FX-62.
If that wasn't bad enough news, we also see that Intel's mid-end E6600 Core2 desktop processor at 2.4 GHz savaged the 2.8 GHz AMD FX-62 on nearly every single benchmark while costing more than three times less. Note that these performance numbers are being echoed by every other hardware enthusiast site on the web. If a 2.4 GHz Core2 can do that much damage, it's hard to imagine what a 3.46 or even 4 GHz Core2 can do. The Core2 processors are already showing some really nice overclocking properties while AMD's FX line doesn't seem to have much room to clock. When I issued the dire warning on AMD back in March, I was blasted by AMD fans for posting dubious numbers from a benchmark set up by Intel but it looks like those numbers were legitimate after all. Considering the fact that even the $224 2.13 GHz E6400 Core2 is giving the AMD FX-62 a run for the money on many benchmarks, AMD is truly in a dire situation and they're under immense pressure to cut prices since Intel has already announced massive price cuts on their legacy Netburst CPUs. Now with the power argument out the window, it would take a miracle to AMD back in the race.
George Ou is Technical Director of ZDNet. See his full profile and disclosure of his industry affiliations.
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