Power Consumption and Temperatures

Power Consumption and Temperatures

So here's where we start the physical testing of the processor. We first quickly look at power consumption in both IDLE and LOAD states and sure, overclocked as well.

IDLE Balanced is the OS configured in BALANCED energy mode, with speedstep throttling down the processor. In IDLE we draw 139W, that's with a Radeon HD 5870 installed, yet the GPU in IDLE.

If we move the Windows 7 or Vista energy mode up to performance we see the wattage rise to 150W still in IDLE. Now once we STRESS the 6 cores we see a power draw of 272W (for the total PC, measured at wall socket). 272W-139W = 133W which matches the advertised TDP.

Once we overclock to 4.4 GHz on all four cores (we'll show you that in the next chapter) things get out of hand much quicker, we now measure a peak of 360W minus 139W from the normal clocked balanced mode = a 221W power draw.

But let's have a look at temperatures.

So here we can see the six cores hyper threaded, 100% stressed in a full Prime95 pass, Turbo mode issues another 133 MHz to the processor, resulting in a 3.4 GHz clock frequency. Now we are water-cooling the processor (semi-passive) with the Zalman Reserator XT. You can see temperatures idle at 25~30 degrees C (77F). And when stressed for a good period of time, we see maximum peak temperatures of roughly 55 degrees C / 130F. We get roughly the same results on a quad-core Core i7 975 on this setup. So it might perhaps be a tiny bit higher but it's really not bad at all.

Let's check out overclocking.