I've read about the 64bit systems (www.tomshardware.com, www.extremetech.com, www.arstechnica.com) a lot and generally they are a bit faster but not much. Unfortunately, to get the true benefit one needs 2 things, a recompiled application (i.e. bryce) and a 64bit OS (new version of Windows XP) Unfortunately, Bryce isn't 64 bit and the 64 bit XP isn't readily available in the stores and you have to do a complete reinstall to get a 32 bit xp into a 64. To make matters worse, most 'old' peripherals don't have drivers for 64 bit XP. This means you may have things like digital cameras, scanners, printers, lan cards, etc. that may not work. Can you stick with a 32 bit XP or Win2K and go with a 64bit Athlon, sure. I am not sure if there is a big advantage, but if you are building new it may work out well if you get a dual core chip. I recommend building your own system if you are up to it. Its a bit more annoying at times and you may have some problems, but not having to worry about having a no-name brand cd burner, motherboard of unknown origin, etc. is nice. You know which manufacturers to go to for drivers and firmware.