[CentOS] x86_64 versus i386

Mon Dec 3 14:53:17 UTC 2007
Nicolas Thierry-Mieg <Nicolas.Thierry-Mieg at imag.fr>

Manish Kathuria wrote:
> How significant are the performance benefits gained by
> using the x86_64 linux instead of i386 on the same system ?

that depends on the software you'll be running
I have a medium-small C project (~20 KLOC), where the x86_64 binary runs 
close to twice as fast as the i386 binary on the same core 2 duo hardware.
speed was important, because this software is used to perform large 
numbers of simulations: bottleneck calculations were implemented as 
bitwise ops, partly in preparation for 64 bit arches, and this 
definitely pays!
so, if you're going to be developing your stuff I'ld recommend x86_64, 
and otherwise you should test whatever software you'll be using the most.
There are just minor annoyances to x86_64 anyways, and you can get 
around them by temporarily installing i386 packages until the x86_64 
issue is resolved (mainly browser-related, also some bugs due to less 
well tested software, eg I recently had a x86_64-specific showstopper 
with openoffice so I switched to the i386 OOo packages)

cheers,
Nicolas