[plug] Gentoo vs Debian

[Craig Ringer]

>>There is a significant difference between optimised code and 
>>un-optimised code; but since every distribution compiles with 
>>optimisation on that isn't an issue.  CPU-specific 
>>optimisations /can/ make a difference for raw computational 
>>stuff (~10-20%) but I didn't notice any subjective 
>>differences in responsiveness or anything.

Interesting. I've found that rebuilding the kernel, glibc, and XFree86 
with optimisations specific to my CPU has given the system a significant 
  boost. Far from massive, but definitely noticeable - especially in 3D 
performance. A kernel rebuild is pretty important for performance, and 
the other two have lesser but definite effects.

YYMV, of course.

Craig