On Fri, Jan 07, 2005 at 01:21:38PM -0600, Steve Bergman wrote: > I am seeking clarification of a point made in the release notes. It > states that FC3 is optimized for Pentium 4. However the kernels and > glibc available are labeled as i686 and i386. I assume, since Pentium 1 > is the minimum hardware requirement, that the instruction set used is > Pentium 1. So: > > 1. What optimization and instruction set are the general packages > actually compiled with? > 2. What optimization and instruction set are glibc-i686 and kernel-i686 > compiled with? (I seem to recall that the kernel is now optimized for size.) > 3. How important is this to someone running a different processor? (Say > Athlon XP.) IIRC p4 has very specific optimization requirements. Currently, the kernel is compiled with -Os (size optimise), with 686 instructions (so that it runs on early pentiums), with instruction scheduling tuned for Pentium 4. In tests I did, -mtune=pentium4 was a win on pretty much everything I tried. Bizarrely in some cases, it even beat -mtune=athlon-xp when I ran it on my athlon. VIA cpus didn't seem to be greatly affected regardless of what the code was tuned for. Dave
