[Gretl-devel] Re: MPI and OpenMP (and openblas?)
Am 16.01.2020 um 19:50 schrieb Sven Schreiber:
Am 16.01.2020 um 17:42 schrieb Allin Cottrell:
> I can't replicate the problem Sven describes, either on Linux or on
> Windows 10.
* Indeed when the --omp-threads=1 option is used, the setting of
OMP_NUM_THREADS makes no difference. This is different to what I had
before, but the machine and the snapshot have changed. (The different
application doesn't matter.) I will re-check on the other machine later.
I now think the differences I saw were spurious, perhaps due to some
additionally running background process or whatever. Some such
fluctuations could be observed, but the "best" runtimes in that
application do indeed not seem to be affected by OMP_NUM_THREADS.
Sorry for the noise there.
The slowdowns of the previous message with Allin's script (e.g.
--omp-threads=2 and OMP_NUM_THREADS=2) were much more drastic, however.
thanks