3 ms·

No, I actually ran it on Arch, but I don't exclude some variation caused by the kernel configuration.

• adrian_b 5y ago
  It is also possible that the benchmark was run on one of the slow cores. Ryzen 9 5900X or 5950X will have a few fast cores, maybe 2 fast cores, which will run a ST task at 4.8 GHz, respectively at 4.9 GHz. If you are lucky, and more likely if you use PBO, the fast cores of your CPU might run at a slightly higher frequency, e.g. by 100 MHz, than guaranteed, especially when you have a good cooler that keeps the CPU at a low temperature. However the rest of the cores will have a lower maximum frequency than the nominal frequency, e.g by 100 MHz or by 200 MHz. The Linux scheduler, at least the default one, does not schedule the threads preferentially on the fast cores, so when running a ST benchmark there are more chances to run it on a slow core than on a fast core. You can determine manually which are your fast cores, by running some single-threaded benchmark pinned successively on each core, e.g. using taskset, while monitoring the clock frequency, e.g. with turbostat. The 1736 value looks like a normal value for a slow core. Rerunning the benchmark, but pinned on a fast core with taskset, should give on a 5950X a value not far from 1850. I have a slower 5900X and with a memory slower than normal (only 2667) and no PBO, but I still get over 1800 on a fast core.