Wed, 08 Jul 2009 22:16:22 +0000, Pauli Virtanen kirjoitti: [clip] > On an older CPU (slower, smaller cache), the situation is slightly > different: > > http://www.iki.fi/pav/tmp/athlon.png > http://www.iki.fi/pav/tmp/athlon.txt > > On average, it's still an improvement in many cases. However, now there > are more regressions. The significant ones (factor of 1/2) are N-D > arrays where the reduction runs over an axis with a small number of > elements.
Part of this seemed (thanks, Valgrind!) to be because of L2 cache misses, which came from forgetting to evaluate also the first reduction iteration in blocks. Fixed -- the regressions are now less severe (most are ~0.8), although for this machine there are still some... -- Pauli Virtanen _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
