64bit vs. 32bit
I was debating a 64 vs 32bit install. Basically for a fair few tasks (including video encoding etc) 64bit is ~10% faster apparently (bigger registers and 16 rather than 8 in i386 help here). But I worried about driver/software support. It’s apparently decent for MythTV, but then I’m planning on an XBMC install to handle iPlayer and maybe last.fm, and I found this:
*) 64bit linux hasn't really been given any real attention. You are advised to use 32bit unless you NEED 64bit for some reason (4GB of RAM is NOT a reason, google "Physical Address Extension"). Some popular problems are; no webserver or httpapi, crashes during navigation, crash opening movie infopanel, crash on some plugins, may not launch at all.
From here. So I guess I’ll stick with 32 bit. Everything that needs a lot of power, and is real time (that’ll be video playback then) should mostly be taken by the GPU with VDPAU anyhow, so the slight performance loss for some tasks shouldn’t matter too much.