3 ms·

While __rdtsc() is fast, be cautious with multi-core benchmarks as TSC synchronization between cores isn't guaranteed on all hardware, especially older systems.

While __rdtsc() is fast, be cautious with multi-core benchmarks as TSC synchronization between cores isn't guaranteed on all hardware, especially older systems. Modern Intel/AMD CPUs have "invariant TSC" which helps, but it's worth checking CPU flags first.

zorked 1y ago
Invariant TSC has been around for over 15 years, probably more.
loeg 1y ago
Rdtsc is fast-ish, but it's still like 10 ns. Something to be aware of if you're trying to measure really small durations (measure 10s or 100s and amortize).