Prime95 is probably the definitive stress test tool, in this test we used an older verion (2.5) simply because it was the version that happened to be on the thumb drive. We ran the standard torture test, that is, we selected the option that produced the max power and heat consumption. Prime 95 utilizes a very intensive mathematical algorithm, with a lot of floating point calculations and, as such, stresses both the front and backend segments of the processor.
This Prime95 profile is a little more interesting than the Cinebench profile collected earlier. The total power drawn from the CPU main is not quite as high as the multithreaded Cinebench R10 loading. The Prime95 power starts at about 102 W and peaks out around 106 W — the very low end of the range for Cinebench. The main difference, however, is the response of the ATX 3.3V and 5.0V inputs, both pulling measurable power during the stress. The +5 VDC line idles around 18 W and, with Prime95, full loads to around 23.8 W, or almost 6 W added to the power distribution, while the 3.3 VDC input goes from idle of 22.8 to about 24.1, a measily but measureable 1.3 W. These increases along the 3.3/5.0 volt lines are, of course, due to activity occuring on the system bus, memory and memory controller. How much of that is partitioned to the CPU itself which needs to be dissipated remains unknown a this time.