NVIDIA GeForce 7800 GTX GPU Review

Transparency AA Image Quality

As I mentioned on the 7800 GTX Features page of this review, NVIDIA is introducing a new technology called Transparency AntiAliasing that attempts to improve image quality on interior lines of textures that are transparent, such as this fence in the prison level of Half-Life 2.  Here I am going to show you side-by-sides of the image quality comparing the setting at OFF to Multisampling, as well as OFF and Supersampling, which are the two methods NVIDIA’s driver is offering. 

Half-Life 2 – Prison

I can see almost no difference going from the OFF setting to the Multisample setting; image quality on the fence links seems to be just as bad as it was before. 

But, by enabling Supersampling mode, we see a big change in the way the chain link fence looks.  It is much smoother and the pixels don’t show near as many jagged lines as they do on the original image.  The “wave” effect as you look down the fence is also gone and I think that any gamer would be able to distinguish this quality difference in the game while they were playing. 

Transparency AA Performance Hit

Of course, nothing comes free in this world, and enabling Supersampling in the NVIDIA driver for Transparency AA does make a difference in your game performance.  But how much?

Multisampling doesn’t see any performance decrement, and that’s expected since we didn’t see any quality changes either.  However, Supersampling does affect your frame rate somewhat, taking us from 163 FPS to 148 FPS, a 15 frame drop.  Also, the minimum frame rate also fell by 18 frames.  So, while we do see some performance degradation with the new Transparency AA turned on, I feel that with the 7800 GTX GPU you should have enough power to enable it and enjoy the improved image quality.

But, bugs?

It’s not all roses — it looks like there might be some growing pains for the Transparency AA as well.  While playing some Far Cry looking for some good examples of the new AA technology at work, I instead found this:

When enabled in Supersample mode, I found that these particular stairs in Far Cry just…disappeared!  I could still walk up them, there textures just weren’t there.  Through out the level there were missing stairs where I thought we would find great examples of new Transparency AA technology. 

These will surely be fixed with a future driver release.