Graphics Interconnect Benchmarks
We use a pair of benchmarks at HEXUS, to measure the performance of the graphics interconnect, which in this case is AGP 3.0. Chosen to hightlight the differences between PCI Express and AGP on the former's introduction last year, the benchmarks are able to highlight any differences in ATI's native AGP and RIALTO-based products on the same interconnect. With TexBench, if you set the texture size high enough, you can overflow card memory and make it texture over AGP. 3D Download simply pushes the card framebuffer back over the bus to the AGP host, and then to the CPU.TexBench
Clocking the X850 XT PE down to 400/500, to match the XL's clocks, shows that when made to texture from locked AGP memory, a native solution is no faster than the bridged RIALTO-based product. That's exactly the desired effect that a bridge chip should have.
3D Download Benchmark
3D Download actually shows the bridged RIALTO-based XL being able to render the framebuffer back to the CPU faster than the native R481-based X850 XT Platinum Edition. Fine performance from the bridged product in this test, too.