On Tue, 2002-11-05 at 17:38, Thomas Dodd wrote: > > > Jean Francois Martinez wrote: > > > I wrote a numerical analysis who was published in february 1999 and > > Is that available online? > > > basically you don't gain 5%. It is closer to 1.5% to 2.5% and this > > when you are running kernel code (when you are running user mode code > > it is unaffected). And since 2002 machines are much bigger than the > > 32 meg box I used as an example the memory savings brought by a kernel > > compile are still more irrelevant > > What compiler? gcc-3 is supposed to have better optimization. > Perhaps the numbers would be different now? > Yesterday I told some things from memory about compiler settings for K6 and it turned that my memory failed me. I reran the tests with gcc 3.2 and basically at -O2 optimization -march=k6 is overall a little better than -mcpu=i686 despite losing for the integer tests and losing heavily at bit operations (not as heavily as I told). But -march=k6 provides better memory bandwidth. It is the floating point tests who end giving a small edge to -march=k6. At -O3 optimization -mcpu=i686 beats -march=k6. Now kernel does not use floating point and it should not be compiled with -O3. :-) JFM -- Psyche-list mailing list Psyche-list@redhat.com https://listman.redhat.com/mailman/listinfo/psyche-list
