http://bugzilla.opensuse.org/show_bug.cgi?id=1177260 Bug ID: 1177260 Summary: Switching python-numpy to plain BLAS causes significant performance regression Classification: openSUSE Product: openSUSE Tumbleweed Version: Current Hardware: Other OS: Other Status: NEW Severity: Normal Priority: P5 - None Component: Basesystem Assignee: screening-team-bugs@suse.de Reporter: stefan.bruens@rwth-aachen.de QA Contact: qa-bugs@suse.de Found By: --- Blocker: --- https://build.opensuse.org/request/show/835366 switched numpy to plain BLAS/LAPACK, which causes a significant performance regression: --- import numpy as np import time n = 4000 start_time = time.time() A = np.random.randn(n,n).astype('float64') B = np.random.randn(n,n).astype('float64') print(" init took {} seconds ".format(time.time() - start_time)) start_time = time.time() m = A@B print(" mmult took {} seconds ".format(time.time() - start_time)) print(np.__config__.show()) --- python3-numpy-1.19.1 with openblas: mmult took 2.4579274654388428 seconds python3-numpy-1.19.2 with blas/lapack: mmult took 877.8246397972107 seconds python3-numpy-1.19.2 with openblas: mmult took 2.6917877197265625 seconds MMult 4000x4000 is 64e9 multiplications and additions, thats ~150kOps/s for BLAS/LAPACK. -- You are receiving this mail because: You are on the CC list for the bug.