Here are the times I get for Magma vs M4RI now. Note the crossover between the two programs is now above about 5000 and M4RI beats Magma below that point. This suggests the remaining factor of 2 is in the Strassen-Winograd function. Probably Winograd-Strassen is falling out of L2 cache (the previous adjustments I made were to prevent the M4R algorithm falling out of L1 cache).
The other possibility is that Magma combines the two algorithms so that there is even greater usage of the Gray code tables. This would be an ugly hack, but could work. 40000x40000: Magma: 112.6s M4RI: 232.4s 20000x20000: Magma: 16.40s M4RI: 32.34s 10000x10000: Magma: 2.750s M4RI: 4.529s 5000x5000: Magma: 0.700s M4RI: 0.672s 2500x2500: Magma: 0.13s M4RI: 0.079s 1250x1250: Magma: 0.015s M4RI: 0.012s 625x625: Magma: 0.0030s M4RI: 0.0023s 312x312: Magma: 0.0014s M4RI: 0.00032s 156x156: Magma: 0.001s M4RI: 0.0001s If I get some time I'll look into this. Did those changes work for you Martin? Bill. On 16 May, 16:24, Martin Albrecht <[EMAIL PROTECTED]> wrote: > On Friday 16 May 2008, Bill Hart wrote: > > > P.S: I also tried cache hints, but no luck. They just slow it down. > > > Bill. > > Bill, thanks so much for looking into this! It is very much appreciated. I'm > going to read/try your patch right away! > > Martin > > PS: I have a slight delay in my replies because my provider's spam filter > consistently flags you and mabshoff as spam for some reason. > > -- > name: Martin Albrecht > _pgp:http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x8EF0DC99 > _www:http://www.informatik.uni-bremen.de/~malb > _jab: [EMAIL PROTECTED] --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
