NVIDIA's GeForce 7800 GTX Hits The Ground Running

Transparency AA, Purevideo, and HDTV

On of the problems with Multisample AA is its inability to correct aliasing within a polygon. One of the main new features that NVIDIA added to the G70 is a method to combat the most notorious problem associated with MSAA: antialiasing of transparent textures.

When transparency AA is enabled on a GeForce 7800 GTX, textures that make use of the alpha channel can be flagged to have either supersample or multisample AA performed inside the texture. This can help a great deal for features often implemented with transparent textures such as leaves, vegetation or chain link fences.

This affords an increased performance hit along with its higher image quality, but no longer will fences, bushes, and trees cause a marked decrease in image quality even while running 4xAA. We will explore the performance hit and quality of Transparency AA in our analysis of the hardware, but NVIDIA provides the option of running with either SSAA or MSAA in this mode. MSAA incurs less of a performance hit, but SSAA is higher quality. We are glad that the choice is left to the end user and would even prefer that we get the choice in how FSAA is performed as well.

With increasingly powerful hardware we can afford to "waste" some cycles on SS in order to achieve slightly higher image quality in game that are severely CPU bound. Check out our recent Insider Article on NVIDIA's upcoming introduction of a 16x AA mode for 7800 GTX SLI systems. We will test this mode as soon as NVIDIA offers a driver with support for it.

This time around, Purevideo has extended support for HD format acceleration. The 7800 GTX will now have support for spatial-temporal de-interlacing for HD content. This feature promises to make 1080i content look that much better on a PC. NVIDIA has also said that the 7800 GTX should support H.264, but have said that the driver will not have support until near year's end. As we have already seen an H.264 demo from ATI, and the lack of anything tangible from NVIDIA at this point is disappointing. We are hesitant to even mention NVIDIA's claimed "support" before we see it running on actual hardware (especially after the lacking and late Purevideo support for initial NV40 parts). This time around, we can expect more support for alternate video players from NVIDIA as they are working with InterVideo and Cyberlink.

Not tied to the 7800 GTX is NVIDIA's latest improvement on HDTV support in their 75 series drivers (also launching today). Over time support for fitting a PC's output to any HDTV has improved, but this latest update makes it that much easier to deal with. Providing sliders and a full screen underscan adjustment feature is long overdue, but we still wish modern hardware could provide a more fully featured plug and play environment for HDTV.

We will also be getting some Windows MCE extensions that make HDTV setups easier to configure as well. If the US can manage to keep broadcast flags off the law books, public support for and adoption of digital television services and computers as media center boxes will surely continue to grow and prosper.