That's my understanding as well, the 64 bit CPUs run cooler. Despite some harsh words on Tom's Hardware, the Athlon XP series still has a good reputation for reliability. I think the Athlon XP will give me consistant performance running Linux. At the end of the day I'm not getting into Debian or DeMuDi to trouble shoot a new board. I just want to build a cheap machine that works with the drivers in the distro.