I guess you could try installing something like the Intel Power Gadget (which, admittedly, hasn't been updated in forever).
Using that tool you can export power consumption, CPU frequency, temperature, and utilization to a csv file for further analysis. Basically: When you stress your computer, do frequencies fall to keep temperatures down? And more importantly: Do they fall below the advertised base clock of the CPU?
I'm not an expert, to be honest. If I recall correctly, some processors are configured to boost only a limited number of cores to remain near their TDP under load. If all cores are used, the CPU would throttle back to respect its TDP value. In other words, a massively parallel task (like a benchmark test) would probably have the effect you observe.I used Intel Extreme Tuning Utility. What I found out is that:
1. As soon as I started the test, the turbo frequency of each core immediately dropped and as soon as the test was done, frequency of each core increased back to near the turbo frequency. Is this normal? Does that mean the cooling system is not good because frequency dropped immediately as soon as I started the test?
2. During the test, frequency of each core dropped to values between the base frequency and the turbo frequency. For example, if the base frequency is 2.8GHz and the turbo frequency is 4.7GHz, starting the test immediately dropped the frequency of each core by 1GHz. Since the frequencies are still above the base clock of the CPU, does that mean there is no thermal throttling even on Intel Extreme Tuning Utility, thermal throttling was highlighted during the test?
3. Is immediately drop of frequency in each core by about 1GHz bad?