Comment by ComputerGuru

__rdtsc drift isn’t an AMD bug, it’s by design. The only way to use the rdtsc instruction is to pin code to the same physical core between calls. They probably just got lucky in that the drift always exceeded the time that elapsed between calls on other cpus or the Linux scheduler’s behavior on Ryzen 7 differs from other CPUs (I’m not familiar with Ryzen 7 but ThreadRipper is basically non-numa and needed patches to the scheduler under Windows to fix some pathological conditions).