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

CPU Only: OCCT With Four Options

OCCT offers a fairly challenging CPU stress test, which often gets overlooked. It might not generate the massive amounts of heat we measure under Prime95 with AVX, but it’s still a great choice for long stability tests. The software can log a number of important parameters, running in an endless loop or stopping after a defined length of time. Download OCCT here.

OCCT With Small Data Set

This option generates the highest load of the four available options, though it's still less taxing than Prime95 with AVX and Small FFTs. We can say, however, that its memory load is greater than Prime95’s.

CPU Package(PECI)Core AverageSensorSocketMemoryCPU (Watts)System (Watts)
Measurement72°C71°C84°C34°C148W219W
Compared to Maximum82.8%82.6%80.0%94.4%86%86.9%
AssessmentHigh package temperature for stability testsHigh memory temperatureMedium CPU and system power consumption
Use forProlonged stability testMemory test (overclocking)

OCCT With Big Data Set

The overall load drops yet again, making this test suitable for laptops that shouldn’t be pushed to their thermal limits.

Memory, specifically, is pushed harder than anything we saw under Prime95. In fact, this is the second-most-taxing memory workload in our suite.

CPU Package(PECI)Core AverageSensorSocketMemoryCPU (Watts)System (Watts)
Measurement62°C61°C72°C35°C113W163W
Compared to Maximum71.3%70.9%68.6%97.2%65.7%64.7%
AssessmentMedium package temperatureVery high memory temperatureSomewhat low CPU and system power consumption
Use forProlonged stability test for mobile devices and mini PCsMemory test (overclocking)

OCCT With Linpack & AVX

OCCT’s AVX implementation generates a demanding overall load, though it doesn’t reach the numbers generated by this utility's own Small Data Set option. Load on the memory is still fairly high, too.

CPU Package(PECI)Core AverageSensorSocketMemoryCPU (Watts)System (Watts)
Measurement68°C67°C75°C34°C130W187W
Compared to Maximum78.2%77.9%71.4%94.4%75.6%74.2%
AssessmentMedium package temperature for stability testsHigh memory temperatureMedium CPU and system power consumption
Use forProlonged stability testMemory test (overclocking)

OCCT With Linpack & SSE

OCCT’s SSE implementation generates a low overall load, similar to the Big Data Set option. But while it doesn't set any new records, this one's a good alternative for lower-end PCs with stock coolers. It’s also a suitable option for prolonged testing.

CPU Package(PECI)Core AverageSensorSocketMemoryCPU (Watts)System (Watts)
Measurement65°C64°C74°C34°C115W172W
Compared to Maximum74.7%74.4%70.5%94.4%66.9%68.3%
AssessmentMedium package temperatureHigh memory temperatureSomewhat low CPU and system power consumption
Use forProlonged stability test for mobile devices and mini PCsMemory test (overclocking)


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