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> RDTSC is directly influenced by frequency scaling

Unfortunate wording, RDTSC itself is not influenced by frequency scaling, it has constant frequency on modern CPUs after all. Your video nicely shows that RDTSC delta is influenced by CPU frequency, as expected, but how does it affect using RDTSC as a clock? On my CPU RDTSC seems to tick at 3GHz, for example. I wonder how precise it is though, how much its frequency can drift from spec.



Ah crud, you're right. What'd really be interesting to see is the ratio between d/dt rdtsc and d/dt clock_monotonic.


I did update my program, now it measures the ratio.




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