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How to Stress-Test CPUs and PCs (Like We Do)

CPU Only: powerMAX With AVX Or SSE & Heavy Load


This combined CPU and GPU stress test wasn’t our first choice when it came to evaluating graphics cards. However, it does do a better job loading down CPUs. Being able to switch easily between AVX and SSE code paths is also a definite plus. Download powerMAX here.

powerMAX With AVX

powerMAX tops out a bit below Prime95 with AVX, but it nearly matches the popular stress test's results. The loads powerMAX generates are well above average, making it a suitable tool for testing CPU coolers. 

Conversely, you won't want to use it for stability-testing overclocked PCs operating close to their limits unless the goal is to identify temperature issues.

CPU Package(PECI)Core AverageSensorSocketMemoryCPU (Watts)System (Watts)
Compared to Maximum90.8%91.9%93.3%77.8%93.0%92.1%
AssessmentHigh package temperatureVery high socket temperatureSomewhat low memory temperatureVery high CPU and system power consumption
Use forCooling test for high-performance coolers

powerMAX With SSE

On our test platform, utilizing the SSE code path resulted in temperatures that averaged ~10°C lower than before. System RAM was the exception; it actually heated up more than when we sent AVX instructions down the CPU's execution pipeline.

CPU Package(PECI)Core AverageSensorSocketMemoryCPU (Watts)System (Watts)
Compared to Maximum79.3%79.1%93.3%83.3%76.7%75.8%
AssessmentMedium package temperatureModerate memory temperatureMedium CPU and system power consumption
Use forStability test for overclocked systems

Heavy Load

Heavy Load works if you're trying to generate a realistic CPU load, and by realistic we mean the types of loads you'd encounter in a game applying average demands to your components. Running Heavy Load won’t tell you anything about your CPU cooler's limits. But it is a decent indicator of how a CPU might fare during everyday operation. It’s also safe to use on older or mobile hardware without worrying about breaking anything. In that sense, it's not really a conventional stress test. Download Heavy Load here.

What the CPU test actually does remains a developer secret. It doesn't seem to explicitly use modern instruction set extensions, though.

CPU Package(PECI)Core AverageSensorSocketMemoryCPU (Watts)System (Watts)
Compared to Maximum66.7%70.9%57.1%83.3%61.0%61.9%
AssessmentLow core and package temperatureModerate memory temperatureSomewhat low CPU and system power consumption
Use forStability test for low-end and older hardwareStability test for low-end mobile devicesSimulation of average everyday loads

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