When we refer to 32-bit or 64-bit processors, what we are talking
about is primarily the size of the registers, tiny, high-speed memory areas
built into the chip.
A 32-bit processor can handle up to 4 billion bytes of memory – an amount rarely
approached in ordinary desktop computing today. By comparison, a 64-bit chip can
address 18 billion billion bytes.
With 64 bit software obviously the way of
the future, the Athlon64 processor allows users to migrate their software over
to 64-bit when they're ready. This contrasts pure 64-bit processors which
translate into expensive purchases of new hardware and new software. With the
Athlon64 processor capable of running 32-bit software now, you can even still
use your favorite 32-bit applications under a 64-bit OS later.
We tested a system based on the highest end of the Athlon 64, the FX-51. The
$733 processor runs at 2.2 gigahertz. AMD built the computer to show off the
new processor.
