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.
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.