what is the difference between 64 and 32 bit data paths?
One bit in the register can reference an individual byte in memory, so a 32-bit system can address a maximum of 4 gigabytes (4,294,967,296 bytes) of RAM. ... A 64-bit register can theoretically reference 18,446,744,073,709,551,616 bytes, or 17,179,869,184 gigabytes (16 exabytes) of memory.