By: Samuel K. Moore
IEEE Spectrum
January 2006
Cell's nine processors make it a supercomputer on a chip
We're flying at about Mach 1.5 around Mount Saint Helens, in
Washington state. IBM Corp. senior programmer Barry L. Minor is at the
controls, rocketing us over the crater and then down to the lake at
its base to skim over the tree trunks that have been floating there
since the volcano exploded over 25 years ago. The flight is
exhilarating, even though it's just a simulation projected on a
widescreen monitor in a cluttered testing lab.
Then, at the flick of a switch, Minor turns the simulation over from
his new Cell processor to a dual-processor Apple Power Mac G5, and the
scenery freezes. The G5 almost audibly groans under the burden, though
it's no slouch. In fact, it's currently the top of the line for
PCs. But Cell is something different entirely. It's a bet on what
consumers will do with data and how best to suit microprocessors to
the task-and it's really, really fast. Cell, which is shorthand for
Cell Broadband Engine Architecture, is a US $400 million joint effort
of IBM, Sony, and Toshiba. It was originally conceived as the
microprocessor to power Sony's third-generation game console,
PlayStation 3, to be released this spring, but it is expected to find
a home in lots of other broadband-connected consumer items and in
servers too.
Executives at Sony Corp., in Tokyo, wanted more than just an
incremental improvement over PlayStation 2's processor, the Emotion
Engine. What they got was a 36-fold acceleration, to a whopping 192
billion floating-point operations per second (192 gigaflops). Because
Cell is a combination of general-purpose and multimedia processors, it
defies an exact comparison with other upcoming chips, but it's thought
to be more powerful than the chips driving competing game systems.
Cell can calculate at such blazing speed, in part, because it's made
up of nine processors on a single chip of silicon, optimized for the
kind of real-time calculations needed in today's broadband, media-rich
environment. A specially designed 300-gigabit-per-second bus knits the
processors into a single machine, and interface technology from Rambus
Inc., Los Altos, Calif., gives it fast access to memory and other
off-chip systems.
So far, microprocessor watchers have been impressed with what they've
seen of Cell. "To bring huge parallel processing onto a single chip in
a clean and efficient way is a real accomplishment," says Ruby B.
Lee, a professor of electrical engineering at Princeton University and
an IEEE Fellow.
http://www.spectrum.ieee.org/jan06/2609
Monty Solomon (monty@roscom.com)