x800xt and 6800Ultra drag performance.

Hot Hardware said:

Where the OpenGL based Doom 3 engine obviously favors NVIDIA's NV40,
ATi's R420 based Radeon X800 XT PE seems to be favored equally here
by Valve Software's new DX9 class graphics engine.

At medium res, there's a smallish 4-5% lead for the X800 XT but add on
4X Anti-Aliasing requirements and 8X Anisotropic Filtering and the flagship
ATi card pulls out an impressive 40% advantage over the Doom 3 dominating
GeForce 6800 Ultra.

Let's scale up the resolution settings and see what the numbers look
like there as well.

There's one word for the lead Radeon X800 XT posts up in these
two tests, "ouch".

The ATi card boasts a 13-14% lead without AA or Aniso on and a
whopping 47% lead with 4X AA and 8X AF enabled. It's amazing to
see how polarized the Doom 3 performance results are versus our
Counter Strike: Source Stress Test results. It's like the two game
engines are at opposite ends of the spectrum when it comes to graphics
processor architectures.

...................

we also know that what has been biting NVIDIA in the backside for so long,
is how well ATi has been able to execute on the delivery of a VPU that
adheres so closely to a strict DX9 architecture.

In short, since all the way back to the R3XX architecture, ATi's DX9 performance
advantage has been their strong suit. As a result, most developers taking the
DX9 code path, have found their game engines running better on ATi hardware,
just like Gabe and the folks at Valve Software have with the Source Engine.

...................

The real story with game engines and these new high end graphics processor
architectures, is probably more about the one constant that never seems to
change over time, resources and money. Game Devs with fewer resources and
smaller budgets, probably have less of an ability to hand tweak their games
for optimal performance on these highly programmable graphics cores.
As a result, a more simplified strict DX9 path may be attractive and that
seems to be where ATi cores shine.

The select few Game Developers that have the resources to get in and optimize
game engine code for NVIDIA's highly flexible NV40/NV45 architecture,
like Id Software and Epic Games, who are also both very effective game
engine marketing machines, will probably deliver engines that will favor
NVIDIA's architecture. Although the raw fill rate and processing power
of the NV40 isn't anymore more robust than the R420, it's strength lies
in it's highly flexible and programmable shader engines.

Click to expand...