On Mon, Apr 09, 2007 at 09:04:21AM -0700, Michael Will wrote: > I saw Spec benchmarks published with portions of it compiled for > 32bit for best results. But the bottom line is that default in 64bit > is faster and some special cases could benefit from 32bit...
Oh, you want a *serious* answer! I don't know for SPECcpu2006, but with SPECcpu2000, a couple of the integer benchmarks ran faster in 32-bit, and none of the floating point benchmarks. Our compiler run 2x faster as a 32-bit binary, because it has very bad cache behavior when pointers get twice as large -- it uses a lot of them. But the general rule is that code is 15% faster in 64-bit, thanks to the extra registers and better calling convention. And a few codes (especially multi-precision integer codes like crypto) benefit from 64-bit integers. -- greg _______________________________________________ Beowulf mailing list, [email protected] To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
