IEEE Spectrum January, 2009 - 24

Multicore Made simple

IntEL'S LarrabEE IS a chIp EVEry dESIgnEr
aLrEady knoWS hoW to program
By Brian Santo & Sally adee

Winner

semiconductors
POWER UP:
larrabee's new
architecture will
enable nextgeneration threedimensional
games and
amplify highend physics
simulations.
illustration:
bryan christie design

chips base on intel's Larrabee architecture aren't on the shelves
yet, but the design is already a hot property because it promises to beat
the chips that game designers now use to model graphics.
And the market for such graphics capability goes beyond video games.
Consider Monsters vs. Aliens, which DreamWorks Animation plans to
release later this year. In classic B-movie style, the film will be in three
dimensions, but this won't be your daddy's 3-D. Because the digital stereoscopic system delivers a different perspective to each eye so deftly, it won't
strain your eyes or turn your stomach. That's why the technology can show
you giants battling not just for minutes at a time but for the entire hour, and
why it'll dominate the market as its '50s-era forerunner never could.
Graphics like these don't happen with commercial off-the-shelf graphics chips, and that's where Intel's Larrabee comes in. It's an architecture, now in late development, for a multicore general-purpose graphicsprocessing unit (GPGPU), one of many in a new category that's sometimes
called a hybrid because it combines the functions of a multicore centralprocessing unit (CPU) with those of a graphics-processing unit (GPU). The
idea is to do the jobs exclusive to each kind without wasting time on interchip chatter. But Larrabee has critical advantages over the other designs.
First, Intel claims that it'll provide greater speed at a lower cost. Second,
Larrabee is based on Intel's x86 architecture, which millions of developers know like the backs of their hands, and it can be programmed in C and
C++, languages they know like the roofs of their mouths. Finally, Larrabee
is backed by the full weight of Intel.
Though graphics applications are what Larrabee's intended for, they
won't be all it ends up doing. Chips based on the Larrabee architecture
may one day allow your computer to watch a sporting event, identify the
players, pick out the most significant, and generate highlight reels automatically. They may enable your laptop to sift through thousands of digital photos, correctly identify the people in each one, and label them so you
can find exactly the snapshots you want. They may even be able to help
researchers manage and then visualize vast amounts of data in such fields
as genetics, geophysics, finance, and computational neuroscience.
to understand what's at stake requires a bit of history. During
the PC's first 15 years or so, its every task was handled by a CPU, the
increasing sophistication of which can be seen in the evolution of computer graphics. In the early years, computer characters and images were
constructed out of giant pixels-think of the first several iterations of
the game character Mario. In the 1980s, Mario was a vaguely humanoid
clump made of squares; by 1996, Super Mario 64 had become a 3-D character limned by smooth curves, drawn in perspective. Computer animation had gained more detail; color palettes had become richer. Virtually
all CPUs and software have evolved to the point where it's no longer
imperative to spend US $200 on a separate graphics card; without one,
you can still get pretty good 3-D graphics.
January 2009 * IEEE SpEctrum * na

Table of Contents for the Digital Edition of IEEE Spectrum January, 2009