Quadruple boot YDL, Gentoo PPC, Mac OS X, Mac OS 9???

[Tim Seufert]

On Saturday, July 19, 2003, at 10:53  AM, Andrew Choong wrote:

> i'm intrigued with gentoo though. probably won't use it all the time,
> but i am VERY curious to see how much faster it supposedly is (as
> compared to YDL) given all this talk regarding optimised compilation 
> etc
> etc.

There may be other benefits to gentoo, but the "faster" argument 
strikes me as crap.  Most of the code in a distribution doesn't need to 
be optimized for a specific CPU, or optimized at all for that matter.  
95% of the code in almost any program, even most programs which need 
high performance, is not performance critical and should really be 
optimized for size rather than speed.  And a huge number of programs in 
any given distribution need no optimization at all, because you aren't 
going to run them but once in a blue moon and they won't take much time 
anyways.  (Does anybody actually care how fast 'cal' prints out a 
calendar?  Didn't think so.)

What's worse for the gentoo case is that when I've messed around with 
GCC optimization flags, I've found that (at least on PowerPC CPUs) the 
best target to use doesn't always match the CPU you're using.  E.G. 
I've had programs that would run faster on a G3 (PowerPC 750) when 
compiled with -mcpu=601 instead of -mcpu=750.  In my experience there's 
every reason to expect that the actual measured results from compiling 
everything with -mcpu=(your CPU type) would be positive for some 
programs and negative for others, with little predictability.

Most of the reported benefits are probably placebo effect.  gentoo 
users believe gentoo should be faster, and that leads to the subjective 
impression that it is faster, even if it's not.