From:
Nicholas C. Weaver
Subject: Reflections on the X-box
It is considerably easier
for Microsoft to make the X-box nearly bug-free when compared to most
of their other products, for the simple reason that the hardware is
under their control and the OS is much simpler. Even though Microsoft
is going to produce it based on one of their existing OSs (probably
NT), the act of cutting out huge volumes of unused and unneeded material
and the necessity of supporting only a small amount of hardware.
The problem with the X-box,
however, is the heavily COTS (Commercial, Off the Shelf) design. Using
a standard CPU, a standard OS, and what will undoubtedly be a modified
version of a standard 3D graphics chip, all save on design cost and
would save on production cost if only a small number are produced.
Yet game consoles sell by
the millions, so the design cost is spread over so many devices and
the cost savings of using COTS parts largely diminishes, since by the
time someone fabricates one million custom CPUs, they don't cost any
more than buying 1M comparable CPUs.
And the performance hit of
using a COTS design is substantial. The Playstation 2's CPU is custom
designed to the task at hand, able to perform a massive number of floating
point calculations/clock cycle. It does not need to run SPEC, it is
not an attractive compiler target for high performance code, and it
is really 3 CPUs in one.
Thus, Toshiba's silicon for
the Playstation 2 drastically outperforms what Intel can possibly provide,
for the specific tasks involved in driving an effective game console.
The additional problem with
the X-box, again introduced by the COTS nature of the system, is the
burden which even a stripped-down Microsoft OS places on the device.
The cost of a hard disk and additional memory are potential killers
when designing a device which should retail for less than $300.
A COTS design by Microsoft
was undoubtedly chosen so they could hurry it out into the marketplace,
but the result will probably be less then spectacular, since Sony's
offering will probably significantly outperform the X-box once applications
are written which can take advantage of the available computational
power.
--
Nicholas C. Weaver
I suspect that Microsoft's
real reason for using a COTS setup is for name-brand recognition, not
necessarily performance. The jury's still out on whether or not it will
work, but I think having a console with an "Intel inside"
sticker might help it sell to a certain crowd.