Hi, Could also be that they are linked to different libs such as atlas and standart Blas. What is the output of numpy.show_config() in the two different python versions.
Jens On Wed, Mar 20, 2013 at 2:14 PM, Daπid <davidmen...@gmail.com> wrote: > Without much detailed knowledge of the topic, I would expect both > versions to give very similar timing, as it is essentially a call to > ATLAS function, not much is done in Python. > > Given this, maybe the difference is in ATLAS itself. How have you > installed it? When you compile ATLAS, it will do some machine-specific > optimisation, but if you have installed a binary chances are that your > version is optimised for a machine quite different from yours. So, two > different installations could have been compiled in different machines > and so one is more suited for your machine. If you want to be sure, I > would try to compile ATLAS (this may be difficult) or check the same > on a very different machine (like an AMD processor, different > architecture...). > > > > Just for reference, on Linux Python 2.7 64 bits can deal with these > matrices easily. > > %timeit mat=np.random.random((6143,6143)); matinv= np.linalg.inv(mat); > res = np.dot(mat, matinv); diff= res-np.eye(6143); print > np.sum(np.abs(diff)) > 2.41799631031e-05 > 1.13955868701e-05 > 3.64338191541e-05 > 1.13484781021e-05 > 1 loops, best of 3: 156 s per loop > > Intel i5, 4 GB of RAM and SSD. ATLAS installed from Fedora repository > (I don't run heavy stuff on this computer). > > On 20 March 2013 14:46, Colin J. Williams <c...@ncf.ca> wrote: > > I have a small program which builds random matrices for increasing matrix > > orders, inverts the matrix and checks the precision of the product. At > some > > point, one would expect operations to fail, when the memory capacity is > > exceeded. In both Python 2.7 and 3.2 matrices of order 3,071 area > handled, > > but not 6,143. > > > > Using wall-clock times, with win32, Python 3.2 is slower than Python 2.7. > > The profiler indicates a problem in the solver. > > > > Done on a Pentium, with 2.7 GHz processor, 2 GB of RAM and 221 GB of free > > disk space. Both Python 3.2.3 and Python 2.7.3 use numpy 1.6.2. > > > > The results are show below. > > > > Colin W. > > > > aaaa_ssss > > 2.7.3 (default, Apr 10 2012, 23:31:26) [MSC v.1500 32 bit (Intel)] > > order= 2 measure ofimprecision= 0.097 Time elapsed (seconds)= > > 0.004143 > > order= 5 measure ofimprecision= 2.207 Time elapsed (seconds)= > > 0.001514 > > order= 11 measure ofimprecision= 2.372 Time elapsed (seconds)= > > 0.001455 > > order= 23 measure ofimprecision= 3.318 Time elapsed (seconds)= > > 0.001608 > > order= 47 measure ofimprecision= 4.257 Time elapsed (seconds)= > > 0.002339 > > order= 95 measure ofimprecision= 4.986 Time elapsed (seconds)= > > 0.005747 > > order= 191 measure ofimprecision= 5.788 Time elapsed (seconds)= > > 0.029974 > > order= 383 measure ofimprecision= 6.765 Time elapsed (seconds)= > > 0.145339 > > order= 767 measure ofimprecision= 7.909 Time elapsed (seconds)= > > 0.841142 > > order= 1535 measure ofimprecision= 8.532 Time elapsed (seconds)= > > 5.793630 > > order= 3071 measure ofimprecision= 9.774 Time elapsed (seconds)= > > 39.559540 > > order= 6143 Process terminated by a MemoryError > > > > Above: 2.7.3 Below: Python 3.2.3 > > > > bbb_bbb > > 3.2.3 (default, Apr 11 2012, 07:15:24) [MSC v.1500 32 bit (Intel)] > > order= 2 measure ofimprecision= 0.000 Time elapsed (seconds)= > > 0.113930 > > order= 5 measure ofimprecision= 1.807 Time elapsed (seconds)= > > 0.001373 > > order= 11 measure ofimprecision= 2.395 Time elapsed (seconds)= > > 0.001468 > > order= 23 measure ofimprecision= 3.073 Time elapsed (seconds)= > > 0.001609 > > order= 47 measure ofimprecision= 5.642 Time elapsed (seconds)= > > 0.002687 > > order= 95 measure ofimprecision= 5.745 Time elapsed (seconds)= > > 0.013510 > > order= 191 measure ofimprecision= 5.866 Time elapsed (seconds)= > > 0.061560 > > order= 383 measure ofimprecision= 7.129 Time elapsed (seconds)= > > 0.418490 > > order= 767 measure ofimprecision= 8.240 Time elapsed (seconds)= > > 3.815713 > > order= 1535 measure ofimprecision= 8.735 Time elapsed (seconds)= > > 27.877270 > > order= 3071 measure ofimprecision= 9.996 Time elapsed > > (seconds)=212.545610 > > order= 6143 Process terminated by a MemoryError > > > > > > > > _______________________________________________ > > NumPy-Discussion mailing list > > NumPy-Discussion@scipy.org > > http://mail.scipy.org/mailman/listinfo/numpy-discussion > > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion >
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