Dear Eric, Thank you for your answer.
On Wed, 20 Feb 2019 at 05:19, Eric Bavier <[email protected]> wrote: > OpenBLAS will use as many threads as the OpenMP runtime will give it, > which is by default one per CPU. I think this default does not take > into account hyperthreads, which htop shows as a separate "cpu". Yes for sure, htop shows hyperthreads number of CPU. :-) Maybe I have wrong, but if hyperthread is activated, then why not use it by default. In other words, OpenMP should be set by default at "hyperthread CPU" and not "physical CPU". I think Debian is doing that for example. What do you think ? > You can set the "OMP_NUM_THREADS" environment variable and OpenBLAS > should pick it up. I don't know whether R does anything for setting > OpenMP runtime settings. I do not know neither. Hum? R does not seems to use OMP_NUM_THREADS. I do not know. All the best, simon
