Fillrate and shading
Let's take a look at the cards' basic vital statistics first.| Card | PowerColor RADEON X800 XL | RADEON X800 XL | ASUS GeForce 6800 Ultra | XFX GeForce 6800 Ultra | RADEON X850 XT PE |
| Interface/speed | PCI-Express x16 | AGP 8x | PCI-Express x16 | PCI-Express x16 | PCI-Express x16 | Onboard memory | 512MB | 256MB | 256MB | 512MB | 256MB | Core speed | 400MHz | 400MHz | 425MHz | 430MHz | 540MHz | Rendering pipelines | 16 | 16 | 16 | 16 | 16 | Fillrate (multi-texturing) | 6.4GTexels/s | 6.4GTexels/s | 6.8GTexels/s | 6.88GTexels/s | 8.64GTexels/s | Memory interface | 256-bit | 256-bit | 256-bit | 256-bit | 256-bit | Memory speed | 980MHz | 980MHz | 1100MHz | 1100MHz | 1180MHz | Memory bandwidth (max) | 31.36GB/s | 31.36GB/s | 35.20GB/s | 35.20GB/s | 37.76GB/s | Retail price | £290 | £210 | £299 | £399 | £325 |
A 512MB framebuffer, when tested with 3DMark05's feature tests run at 1024x768x32, shouldn't show a great deal of performance deviation from an similarly-clocked X800 XL with a 256MB framebuffer.
As expected, when evaluated in single- and multi-texturing tests, both X800 XLs perform to within 1% of each other.
The reality fits theory well. A 512MB framebuffer will show its worth when movements of texture and vertex data are consistenly over 256MB.
