Unfortunately this is default openblas configuration, and it is outside of our control, as far as I know.
On Fri, 22 May 2020 at 14:18, Zhou Jiaqi firstname.lastname@example.org wrote:
Thank you very much for your timely reply. I find that OPENBLAS_NUM_THREADS=1 is quite effective, it can enforce the calculation to be in 1 thread and improve the efficiency by 3 times. Thanks for advice !
Still there remains a problem : When I use a normal instruction, i.e. ‘python kwant.py’ to run, it starts many threads and results in low speed. However, when I use ‘OPENBLAS_NUM_THREADS=1 python kwant.py’, it starts only 1 thread and results in high speed. I am quite confused about why the normal instruction involves many threads, as well as presents an unsatisfactory performance.
The procedure I installed Kwant : sudo apt-get install libmumps-scotch-dev # for MUMPS python setup.py build python setup.py install
Thanks again for your help !