[lug] Re: athlon to athlon-xp

[Andrew Jenkins]

jd wrote: 
> Hello,
>  I have a rh7.3 box running a 2.4.18-3 kernel running on a 
> Athlon 1.2ghz chip and the kt266a chipset. I just received
> a Athlon-XP 2000+ and have replaced the older 1.2 with it.
> 
> Is there anything i can do to optimize my system for this new chip
> ....like recompiling kernel for the SSE flag or something ? :)
> 
> any suggestions appreciated.
> 
> Thanks,
> jd

I'm in the middle of a linuxfromscratch for my Athlon XP 2000+, and I notice
significant performance boosts over RedHat 8.0 or Debian by using:

CFLAGS='-fomit-frame-pointer -mfancy-math-387 -mcpu=athlon-xp -O3 -mfpmath=sse
-m3dnow -msse'

This makes debugging, I believe, impossible, but I don't debug much.  the last
two flags, according to GCC, enable those machine instructions but don't
automatically make use of them.
I find lots of performance boosts by recompiling certain packages, especially
XFree86 and GTK+.  Mozilla seems to benefit from an optimized source compile,
too.  If you use XMMS or Xine, definitely recompile those with -msse -m3dnow
-mcpu=athlon-xp -mfpmath=sse, you'll notice a big speedup.
There isn't a kernel configure option in 2.4 or 2.5 that allows for athlon-xp
specific compiles, but you can edit the Makefile and add -mcpu=athlon-xp to the
HOSTCFLAGS.  I don't know if GCC technically distinguishes between athlon and
athlon-xp, so this might not change much.