|
The 64-bit thangy is the width of the data bus. The wider the bus, the more data you can transfer with a clock edge. That makes for a performance increase. While machines may have an address bus the same width, it ain't necessarily so. The width of the address bus, how many of them are brought outside the device, and how many are wired up will determine the general memory space. Some systems will set aside part of the space available for memory-mapped I/O, also.
|