What is meant in Newegg's descriptions of processors by "64-bit support"? I know that 32-bit processors can handle 64-bit (or even 128-bit variables). Does this refer to memory allocation? That is, is it able to reference memory addresses beyond 4 GB when a processor that has no 64-bit support can't? Or, does it refer to it being faster with 64-bit variables? Windows calculator uses a 128-bit floating point variable since Windows 98 at the earliest known (back when 16-bit processors were probably still in use).