CPU Only: Measuring Power Consumption With Different Stress Tests
Regardless of whether you're talking about CPUs or graphics cards, the general principle remains the same: however much energy is put in reemerges as waste heat.
To that end, we start by observing the CPU's power consumption via its package. Differences between various architectures and models can be massive. But our Core i7-8700 does a fairly good job of representing the upper-mid-range, given its 65W TDP.
Prime95 with AVX and Small FFTs takes first place in our comparison of stress tests, followed by powerMAX with AVX and AIDA64’s FPU test.
The top three finishers land in their same positions, though the rest of the field shuffles around a bit. This is due to variances in certain loads, such as the memory tests. Moreover, there are slightly different voltage converter losses attributable to dissimilar load patterns.
We decided to present the deltas between overall power consumption and individual results as well, since some of them are pretty massive. This comparison allows for an estimate of how much additional waste heat is generated by the system that the CPU cooler can't take care of. Keep these numbers in mind if you're building a water-cooled system; proper ventilation is how you'll have to cope with the extra heat.
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