Sebastian, Optimization appears to be important here. I used no optimization in my previous post, so you could try the -O3 compile option:
gcc -O3 -c my_lib.c -fPIC -fopenmp -ffast-math for na=329 and nb=340 I get (about 7.5 speedup) c_threads 1 time 0.00103106021881 c_threads 2 time 0.000528309345245 c_threads 3 time 0.000362541675568 c_threads 4 time 0.00028993844986 c_threads 5 time 0.000287840366364 c_threads 6 time 0.000264899730682 c_threads 7 time 0.000244019031525 c_threads 8 time 0.000242137908936 c_threads 9 time 0.000232398509979 c_threads 10 time 0.000227460861206 c_threads 11 time 0.00021938085556 c_threads 12 time 0.000216970443726 c_threads 13 time 0.000215198993683 c_threads 14 time 0.00021940946579 c_threads 15 time 0.000204219818115 c_threads 16 time 0.000216958522797 c_threads 17 time 0.000219728946686 c_threads 18 time 0.000199990272522 c_threads 19 time 0.000157492160797 c_threads 20 time 0.000171000957489 c_threads 21 time 0.000147500038147 c_threads 22 time 0.000141770839691 c_threads 23 time 0.000137741565704 for na=3290 and nb=3400 (about 11.5 speedup) c_threads 1 time 0.100258581638 c_threads 2 time 0.0501346611977 c_threads 3 time 0.0335096096992 c_threads 4 time 0.0253720903397 c_threads 5 time 0.0208190107346 c_threads 6 time 0.0173784399033 c_threads 7 time 0.0148811817169 c_threads 8 time 0.0130474209785 c_threads 9 time 0.011598110199 c_threads 10 time 0.0104278612137 c_threads 11 time 0.00950778007507 c_threads 12 time 0.00870131969452 c_threads 13 time 0.015882730484 c_threads 14 time 0.0148504400253 c_threads 15 time 0.0139465212822 c_threads 16 time 0.0130301308632 c_threads 17 time 0.012240819931 c_threads 18 time 0.011567029953 c_threads 19 time 0.0109891605377 c_threads 20 time 0.0104281497002 c_threads 21 time 0.00992572069168 c_threads 22 time 0.00957406997681 c_threads 23 time 0.00936627149582 for na=329 and nb=340, cdist comes in at 0.00111914873123 which is 1.085x slower than the c version for my system. for na=3290 and nb=3400 cdist gives 0.143441538811 Cheers, Eric _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion