MaximumPC 2004 12

B

ack when 3D acceleration was young

and Bill Gates’ net worth was still less

than $100 billion, a little company

named 3dfx released a videocard called

the Voodoo2. Although ludicrously slow

by today’s standards, the Voodoo2 was

terrifi cally fast for its time, but its incredible

speed was only half of what made it special.

In one of the fi rst consumer-level uses of

SLI ( scan-line interleave ) technology,

intrepid gamers could pair two Voodoo2

cards together and gain close to a 100

percent increase in performance.

Unfortunately for gamers, the PCI slot—

which simply couldn’t provide enough

bandwidth to satisfy the increasing demand

for larger textures and more complex

models—was phased out for graphics soon

after the Voodoo2 release. Its replacement,

the AGP bus, allowed for only a single AGP

slot per system, effectively putting the

kibosh on multi-card setups. Buh-bye, SLI.

Fast forward eight years. The AGP bus

is rapidly approaching its own ceiling. Its

replacement, the shiny, new PCI Express

bus, boasts higher transfer speeds and fully

bi-directional transfers. But the really big

news about the PCI Express

spec is that it restores the

option of connecting more than one

videocard to suitably equipped PCs.

In our September issue, we reported

that nVidia was preparing a new dual-

card approach to 3D video, and promised

hard Lab results to come. Well, folks,

it’s time—we recently received the very

fi rst SLI-equipped (SLI is now marketese

for scalable link interface ) reference

system, and we’ve taken it into the Lab for

a series of brutal hands-on tests that only

Maximum PC can deliver.

Stunning Performance

The machine we used to test nVidia’s SLI

solution is a 3.4GHz Xeon on an Intel

E7525 chipset with 1GB of registered

DDR memory. The nVidia solution differs

from Alienware’s yet-to-be-released dual-

card confi g (reported on in the June 2004

issue) in one important way. Instead of

rendering half of the screen with each card,

then using an external device to combine

the two half screens, the nVidia boards

communicate directly with each other

using a special internal SLI connector. This

high-bandwidth link between the two

boards allows them to share their onboard

memory and communicate faster than they

could even over the PCI Express bus. At

press time, we had yet to test the Alienware

solution, but our hunch is that nVidia’s

interconnect makes for more effi cient

rendering and faster performance. (By

contrast, Alienware’s tech allows you to plug

in either ATI or nVidia cards—although not

at the same time.)

The Maximum PC Lab can be a pretty

pragmatic place, but the performance gains

we saw stunned us into the sort of euphoric

numbness we rarely experience. The SLI

confi guration nearly doubled the results

of an otherwise identical single-card rig in

most of the benchmarks we ran. But wait, it

gets better: We knocked out an astounding

63.6fps(!) in Doom 3 at 1600x1200 with 4x

AA and 8x anisotropic fi ltering enabled, and

a whopping 20,007 score in 3DMark 2003.

Holy. Cow.

There’s a catch, though. In order to

see performance gains—even in graphics-

intensive games like Doom 3 —you have to

really crank up your resolution and anti-

aliasing settings. Even at 1280x1024 on

our test machine, Doom 3 was constrained

by the performance of the CPU. It wasn’t

until we upped the resolution to 1600x1200

In the Lab

Is nVidia’s hyper-expensive

dual-card rig worth the cost?

After testing the first SLI-

equipped reference system,

the Maximum PC Lab

answers the question with a

resounding “ YES!”

 MA XIMUMPC DECEMBER 2004

0ut a pair of Ge&orces in a well-

eQuipped mobo and youll be ready

to ride the S,) love train. Theres

a reason we named this

configuration our videocard Gear

Of The 9ear winner and that reason

is speed.

World Exclusive:

Dual GeForce 6800s!

A behind-the-scenes look at Maximum PC testing

WHAT ABOUT MULTIPLE MONITORS?

Once we satisfi ed our questions about performance, we eagerly set out to learn whether we

could set up a four-monitor confi guration by connecting the displays to the two nVidia cards’

dual-outputs. Multi-mon afi cionados will be glad to know that nVidia’s SLI solution works

splendidly. We plugged in the four monitors, rebooted the machine, and were up and running

with a panoramic four-head display that didn’t exhibit any of the 2D performance woes that multi-

mon displays typically exhibit when multiple PCI cards are involved.

The new 2 edition of 3DMark brings

mortal systems to their knees but our

S,) rig churned through the benchmark

without incident and reported the

highest scores weve seen to date.