Q: My motherboard is x64 capable and my CPU is Intel Celeron 440 @ 2.00GHz. I've always been running x86 operating systems, but can I run a x64 OS, like Windows XP or Vista x64 instead of 32-bit versions? Because I hear that they perform better than 32-bit versions, is that true? Thanks in advance.
A: If you sat at an 64 bit install of windows XP, and a 32 bit install of windows XP you would notice very little difference. First your processor is not capable of the 64 bit instruction list. So you can not install a 64 bit os. http://www.intel.com/products/processor_number/chart/celeron_M.htm The only thing that 64 bit OS offers, is more memory registry, and an extra degree of floating point. So if you have a database program, or cad, or some scientific program. Then 64 bit OS will be a faster number cruncher, and give you much more support for larger ram. You won't see a huge difference in anything else. Also don't confuse x64 with x86. Too very different things. X86 refers to the 8086, which is intel's first major microprocessor, which all modern intel chips are descended from. (yes amd reverse-engineer intel's chip, aka stole the design). X64- referes to the x86-64 instruction set. This is the instruction list for doing all 64bit micro-ops.