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