(Apologies if this has been fixed in trunk; I base this on 1.4.0 and no related comments of MKL on the mailing list) I finally got the latest version of MKL working. What appears to have changed is that the MKL shared libraries will themselves dynamically load different other libraries, depending on the detected CPU. This is in some ways great news for me, because it means I can avoid worrying about miscompiles when compiling one single version of NumPy/SciPy to use for our heterogenous cluster. So I'd rather *not* link statically [1]. Anyway, after modifying site.cfg [2], things almost work, but not quite. The problem is that Python by default imports shared libs using RTLD_LOCAL. With this patch to NumPy it does: Change in numpy/linalg/linalg.py: from numpy.linalg import lapack_lite to: try: import sys import ctypes _old_rtld = sys.getdlopenflags() sys.setdlopenflags(_old_rtld|ctypes.RTLD_GLOBAL) from numpy.linalg import lapack_lite finally: sys.setdlopenflags(_old_rtld) del sys; del ctypes; del _old_rtld Questions: a) Should I submit a patch? b) Negative consequences? Perhaps another Python module can now not load a different BLAS implementation? (That still seems better than not being able to use MKL IMO). c) Should this only be enabled by a flag somewhere? Where? Or can one just do it regardless of BLAS? d) Do I need a "if hasattr" for Windows, or will Windows just ignore it, or does this apply to Windows too? [1] BTW, I could not figure out how to link statically if I wanted -- is "search_static_first = 1" supposed to work? Perhaps MKL will insist on loading some parts dynamically even then *shrug*. Dag Sverre