How can I measure sustained CPU performance on my PC?

For sustained CPU performance, I would use a combination of a real workload and hardware monitoring rather than relying only on a short benchmark.

A simple approach would be:

1. Start HWiNFO in Sensors mode and monitor/log:
   
   
• CPU Effective Clock
• CPU Package Power
• Core/Package Temperature
• CPU Utilization
• Thermal Throttling / Power Limit flags
2. Run a sustained CPU workload for 30–60 minutes.

For a realistic workload, a long HandBrake software encode is a good option because it represents something closer to actual CPU usage than a short synthetic benchmark.

For a more repeatable stress test, OCCT CPU or CPU+RAM can also be used for the same period.

The important part is not only the maximum clock speed. I would compare the first few minutes of the test with the last 10–15 minutes.

If CPU utilization remains close to 100% but the effective clock gradually decreases while temperature or power-limit flags become active, then the CPU is most likely being limited by thermal or power constraints.

I would also record:

• Average effective clock during the test
• Maximum temperature
• Sustained package power
• Any thermal/power throttling events
• Total workload completion time

This gives a much better indication of sustained performance than a single short benchmark score.

For gaming specifically, I would test separately, as most games do not generate the same sustained all-core CPU load and the result can also be limited by the GPU.