Fillrate and shading
Let's take a look at the cards' basic vital statistics.| Card | XFX GeForce 6800 Ultra | ATI RADEON X850 XT PE | GeForce 6800 Ultra | GeForce 7800 GTX |
| Interface/speed | PCI-Express | PCI-Express | PCI-Express | PCI-Express | Onboard memory | 512MB | 256MB | 256MB | 256MB | Core speed | 430MHz | 540MHz | 425MHz | 430MHz | Rendering pipelines | 16 | 16 | 16 | 24 | Fillrate (multi-texturing) | 6.88GTexels/s | 8.64GTexels/s | 6.80GTexels/s | 10.32GTexels/s | Memory interface | 256-bit | 256-bit | 256-bit | 256-bit | Memory speed | 1050MHz | 1180MHz | 1100MHz | 1200MHz | Memory bandwidth (max) | 33.6GB/s | 37.76GB/s | 35.2GB/s | 38.4GB/s | Cheapest online price | £470 | £330 | £330 | £390 |
The cost of additional memory pushes the card's price to above GeForce 7800 GTX levels. Potential buyers contemplating a purchase of a 512MB-equipped GeForce 6800 Ultra need to bear the 7800 GTX's performance in mind when evaluating which SKU to go for.
Let's take a look at fillrate and shading performance. These figures often give us an idea of how a card will perform with modern games. Shading is where it's currently at.
As one would expect when tested at 1024x768 and with no image enhancement, there's very little to choose between the single- and multi-texturing fillrate of either GeForce 6800 Ultra card, be it 256MB or 512MB. The cyan line represents NVIDIA's GeForce 7800 GTX card, which is far and away the most impressive here.
Pixel shading is also roughly analagous to a 256MB Ultra's. The slight increase, we suppose, can be put down to the XFX's 5MHz faster core speed. The pixel shading prowess of the cheaper 7800 GTX is beyond reproach.
Vertex shading, too, is where would would expect it. What these results infer is that the usefulness of a larger framebuffer won't be apparent until resolution and image enhancement are turned way, way up.
