From: "M. Edward (Ed) Borasky" <znmeb@...>
Date: 2008-08-16T13:04:51+09:00
Subject: [ruby-core:18316] Re: Ruby 1.8.6 yields 50%-100% performance	gain when compiled at full optimization

On Sat, 2008-08-16 at 03:39 +0900, Shot (Piotr Szotkowski) wrote:
> kevin nolan:
> 
> > control: ruby 1.8.6 (2007-09-24 patchlevel 111) [x86_64-linux]
> > (apt-get install ruby)
> > test:    ruby 1.8.6 (2008-08-11 patchlevel 287) [x86_64-linux]
> > (source compiled with '-O3 -mtune=K8 -march=K8')
> 
> Are you sure the differences are not because of the --with-phtreads
> flag in Ubuntu���s build? In my case, the difference between Ubuntu���s
> Ruby and `configure; make; make install` 1.8.6.p111 was about 40%
> (without touching -O, -mtune and -march).

Last time I looked, the difference between no optimization whatsoever
and "-O3 -march=<your chip here>" was about 30 percent. But yes,
pthreads makes a big difference. And I think pthreads is mandatory for
1.9.

BTW ... 64-bit compiled is slower than 32-bit compiled on a 64-bit chip,
too ... cache sizes, alignments, and such, I suspect, though I haven't
taken the time to profile it.
-- 
M. Edward (Ed) Borasky
ruby-perspectives.blogspot.com

"A mathematician is a machine for turning coffee into theorems." --
Alfr��d R��nyi via Paul Erd��s