IIRC, current x86-64 chips are limited to 48bits virtual address to simplify the address translation logic (cheaper to manufacture). This makes sense for the c

IIRC, current x86-64 chips are limited to 48bits virtual address to simplify the address translation logic (cheaper to manufacture). This makes sense for the current generation of storage sub-systems, though it would be misleading to say using memory map technology will be "obsolete in half a decade". The 48 bit limit is arbitrary. Manufacturers have 56 bit designs on the table right now, and there is nothing stopping them from implementing full 64 bit virtual address support.