ATI Radeon X1900 XTX And CrossFire: R580 Is Here

Here we have yet another set of screen shots for your inspection. In this batch of images, we want to compare NVIDIA's and ATI's dual-GPU anti-aliasing techniques. NVIDIA calls it SLIAA and ATI SuperAA. These modes are only enabled when using a pair of cards together, either in SLI or CrossFire modes, because each card renders the same frame before they are blended together.  For more details on these anti-aliasing modes, take a look at this article on SLIAA and this one outlining the new features introduced with ATI's CrossFire.

Image Quality Analysis: SLI & CrossFire Anti-Aliasing Modes Still More NVIDIA vs. ATI

GeForce 7800 GTX SLI 1280x1024 - No AA

GeForce 7800 GTX SLI 1280x1024 - SLI8X AA

GeForce 7800 GTX SLI 1280x1024 - SLI16X AA

Radeon X1900 CrossFire 1280x1024 - 8X Super AA

Radeon X1900 CrossFire 1280x1024 - 10X SuperAA

Radeon X1900 CrossFire 1280x1024 - 12X Super AA

Radeon X1900 CrossFire 1280x1024 - 14X Super AA

There are three portions of the screen to focus on these screen shots - the cables, the tree, and the scaffolding under the bridge in the distance. Our favorite modes would unquestionably be ATI's 10X and 14X SuperAA modes because they do an excellent job in eliminating jaggies in the cables and preserving fine detail under the bridge, but the trees lose more and more detail as the level of AA is increased.

We didn't perform a comprehensive test routine to assess the performance of all of ATI's CrossFire SuperAA modes with the X1900, but we did run a couple of tests to get a general idea as to how the various modes perform. The new revision of the compositing engine introduced on the X1800 XT Master Card, and used on the X1900, offers higher-performance in SuperAA modes than the engine used on the X850 XT, because the compositing engine can do the final blend with each individual card running at full speed.

CrossFire AA Performance: Half Life 2 & FarCry Upping the Number of Samples

As you can clearly see, as the level of anti-aliasing is increased NVIDIA's SLIAA has a much more dramatic effect on performance. SLI16X AA is playable in both games at 1280x1024, but ATI's 14X AA offers much better frame rates. Basically, if a single Radeon X1900 XT is capable of playable frame rates in a game with a certain level of anti-aliasing, adding a master card and running in CrossFire mode will offer the same frame rates with virtually double the amount of anti-aliasing applied to the scene.

GeForce 7800 GTX SLI 1280x1024 - SLI16X AA w/ 16X Aniso & Trans. AA

Radeon X1900 CrossFire 1280x1024 - 14X Super AA w/ 16X HQ Aniso & Adaptive AA

As a final treat for the image quality fanatics among you, we snapped off two final screen shots with each platform configured for the best image quality.  On our GeForce 7800 GTX SLI rig, we enabled 16X SLIAA, transparency anti-aliasing, and maxed out the anisotropic filtering. On the X1900 CrossFire rid we enabled 14X SuperAA with high quality adaptive anti-aliasing and high quality 16X anisotropic filtering. The SLI rig has the best fine detail under the bridge, and in the trees, but ATI does a better job with the aniso. Look at the sloping hill to the right and you'll see what we mean. Believe it or not, both platforms produced very good frame rates in Half Life 2 at these settings and resolution too. The CrossFire rig could run the game at 1280x1024 with these "ultra high quality" settings at over 125 FPS, whereas the SLI rig's performance hovered around 85 FPS.