reviews TESTED. REVIEWED. VERDICTIZED
60 MA XIMUMPC MARCH 2006
A
TI’s CrossFire technology finally gave
ATI a dual-GPU solution. And even
as we greeted the Radeon X850
XT CrossFire Edition with a barely stifled
yawn, we held out hope that the X1800 XT
CrossFire Edition would help the company
advance down the field. No such luck.
This is not to say that ATI has completely
fumbled the ball: A single 512MB X1800
XT is certainly fast, and pairing one with a
CrossFire master card boosts performance
anywhere from 24- to 73 percent. It’s just
that two X1800 XTs running in CrossFire
mode deliver benchmark results that are well
behind a pair of nVidia’s 512MB GeForce
7800 GTXs in SLI. And now that nVidia has
figured out how to run four GPUs in a single
system (turn to page TK in the QuickStart
section of this issue for the full story), nVidia
has moved the goal posts even further.
We think at least part of the perfor-
mance shortcoming can be attributed to
ATI’s own core-logic chipset. We bench-
marked the X1800 XT CrossFire solo first
in our default test bed—an nForce4 system
(an Asus A8N-SLI Deluxe motherboard, a
2.6GHz AMD Athlon 64 FX-55, and 2GB of
DDR400 RAM)—and then in an ATI Radeon
Xpress 200 environment (using Sapphire
Technology’s Pure CrossFire PC-A9RD480
motherboard with an identical CPU and
RAM). The card performed about two per-
cent faster in the Asus motherboard.
If you’re not interested in AMD com-
patibility, ATI has also certified CrossFirefor use in mother-
boards with Intel
chipsets. ATI tells us
it has also provided
some of its system
integrator partners with Catalyst drivers
that support motherboards with nVidia’s
nForce4 chipset. These special drivers are
not available to the general public—and
ATI doesn’t plan to release them.Ignoring the negligible 2 percent perfor-
mance deficit between ATI and nVidia chip-
sets, both 1800 XT cards we tested lagged
behind a single 512MB GeForce 7800 GTX
running on the same motherboard. The
stand-alone Sapphire card was 9.4 percent
slower running 3DMark05 , for example.
Even though ATI’s OpenGL drivers have
improved considerably, the Sapphire card
ran nearly 22 percent slower than eVGA’s
512MB GeForce 7800 GTX card in Doom 3.
Pairing Sapphire’s card with ATI’s X1800 XT
master card boosted Doom 3 performance
from 60.1fps to 87.2fps, but
those frame rates are still
12fps slower than a pair of
512MB 7800 GTX cards in SLI.
ATI stacks up better when
you compare two 512MB
X1800 XT cards running in
CrossFire mode to two 256MB
7800 GTX cards running in SLI.
The eVGA eGeForce 7800 GTX
KO boards we tested were
not significantly faster than
the ATI/Sapphire pairing in
most tests, and the CrossFiresystem’s 3DMark05 score topped that of the
SLI rig by nearly 3 percent.
Returning to the subject of drivers,
ATI makes it easy for anyone to overclock
an XT-class videocard right from withinATI Radeon X1800
XT Crossfire Edition
It’s better, but this card’s still playing second fiddle
X1800 XT GEFORCE 7800
CROSSFIRE GTX 512MB IN SLIBest scores in each category are bolded. Halo tested at 1600x1200 with sound disabled.
Doom 3 tested at High Quality, 1600x1200, 4x AA. Far Cry and 3DMark03 Game 2 and Game
4 tested at 1600x1200, 4x AA, 8x aniso. 3DMark03 and 3DMark05 run using default settings.DOOM 3 (FPS) 87.2 99.2
FAR CRY (FPS) 158.9 153.3
HALO (FPS) 139.9 138.6
3DMARK05 11,985 12,526
3DMARK03 27,477 32,094
3DMARK03, GAME 2 (FPS) 73.9 92.6
3DMAKR03, GAME 4 (FPS) 103.7 129.6
HQV SCORE 93 56BENCHMARKS
Sapphire Technology’s Radeon X1800 XT was the second GPU in
our test system.SPECS
'PU ATI X1800 XT
MEMOR9 512MB GDDR3
CORE 594MHz stock (tested at
C,OC+ 624MHz)3PEED (^)
MEMOR9 693MHz (tested at 797MHz)
C,OC+
3PEED