P
hysics acceleration was the hot
topic at this year’s Game Developers
Conference. Intel and AMD were talking up
the idea of running physics off a second or
third CPU core in multicore systems. ATI and
nVidia were pitching their high-end GPUs for
the job. And Ageia, which makes the only
dedicated physics accelerator—the PhysX
chip—was claiming its card was the only
chip for the job.
In addition to announcing that its long-awaited PhysX card was finally shipping,
Aegia revealed that BFG Technologies had
joined Asus in offering add-in boards. It
was also announced that Dell, Alienware
(now a division of Dell), and Falcon
Northwest would begin selling rigs with
PhysX boards. If all goes according to plan,
upgraders and DIY system builders should
be able to get their hands on an add-in card
by the time you read this.
nVidia sought to rain on Aegia’s parade
by announcing an “exclu-
sive co-marketing deal”
with physics middleware-
developer Havok—a
purely paper arrangement
of dubious value to con-
sumers. Representatives
from the two companies
showed several fairly
crude demos developed
with Havok’s Havok FX
software running on two
nVidia GeForce 7900 GTs
in SLI. This left ATI in the
unenviable position of
screening closed-door
PowerPoint presenta-
tions of its GPU doing
physics. ATI originally
mentioned the notion of
using a GPU for physics
processing in October, atthe launch of the X1000 series.
nVidia’s deal with Havok was a shrewd
move, because it created the impression
that Havok FX would work only with nVidia
hardware. In reality, Havok FX will work
with any Shader Model 3.0-class GPU,
including any of ATI’s X1000 parts. What’s
more, the middleware doesn’t rely on the
type of high-speed GPU-to-GPU com-
munication that SLI—or CrossFire, for that
matter—requires. Theoretically speaking,
you could upgrade your videocard, leave
the old one in the box, and dedicate it to
physics processing.
Naturally, ATI and nVidia are claiming
each others’ technology isn’t suited to
physics acceleration. For example, ATI has
stated that its X1000 series of cards are
superior because they’re capable of more
granular branching (compared with nVidia’s
card). However, Nick Stam, nVidia’s direc-
tor of technical marketing, told journalists
at GDC that ATI’s decision to build such a
complex GPU was foolish, saying the cost
of “...adding those features is too high for
a minimal performance return in today’s
apps and even for upcoming apps.”
So which component—CPU, GPU,
or PPU—is best suited for physics? It’s
going to take a little time and a bunch
of benchmark testing before anyone can
authoritatively say, but we’ll have an
answer very soon.GDC 2006:
It’s All About
Physics
8 MA XIMUMPC JUNE 2006
If even half the seeds planted at the 2006
Game Developers Conference germinate,
physics will be as important to tomorrow’s
games as 3D graphics are today
quick startTHE BEGINNING OF THE MAGAZINE, WHERE ARTICLES ARE SMALL
Ageia (finally) launched its PhysX
processor at this year’s Game
Developers Conference. The card
will reportedly sell for $250 at retail.Ageia showed a few custom-made game demos running
its PhysX accelerator, and the results were impressive.
Whether its performance will be as impressive in shipping
titles remains to be seen.