ATI Radeon Xpress 200: Performance, PCI Express & DX9 for Athlon 64

ATI X800 XT PCIe: nVidia nForce4 vs. ATI Bullhead

nVidia introduced nForce4 several weeks ago as their PCI Express updated version of the nForce chipset for Athlon 64. In nForce4: PCI Express and SLI for Athlon 64, we concluded the performance of nForce 4 and nForce3 Ultra was basically the same. However, with nForce4 sporting PCI Express graphics, we have the opportunity to compare the same PCIe video card directly on both systems. We first compared performance of the ATI X800 XT PCIe on both the ATI Bullhead Reference board and the nVidia nForce4 Reference board.

ATI X800 XT (PCIe), nVidia nForce4 vs. ATI Bullhead FX55, 2X512MB, 2-2-2-10 DDR
Benchmark	nVidia nForce4	ATI Bullhead ATI RX480	% Change nF4 to ATI
Halo	106.6	121.9	+14.4%
UT2004 - High Quality	74.0	74.4	+0.5%
Doom3 - High Quality	102.5	97.9	-4.5%
Far Cry 1.1	158.9	168.6	+6.1%
RTCW - Enemy Territory Radar	114.0	115.3	+1.1%

There are some very interesting results comparing ATI PCIe video on both systems. First, we see that Far Cry is still slower on nVidia, even with the ATI PCIe video card. This leads us to conclude that at least part of the performance hit that we see with Far Cry is a result of nVidia chipset or driver code. We see a similar anomaly in Doom 3 being slower with the ATI card on the ATI than it is with ATI on nVidia. Since everything else is the same in both setups, we again would look to ATI drivers or chipset code as the likely issue.

Halo is a significant 14.4% slower on nVidia/ATI than on ATI/ATI, but you will see in later benchmarks that nVidia PCIe on nVidia is roughly equivalent in performance to ATI PCIe on ATI. In the larger picture, this is a driver/code issue worth a look by manufacturers, but it doesn't reflect any real performance differences in these chipsets. Overall, the ATI Bullhead can be considered equivalent to a bit faster in performance than nForce 4 with both running an ATI PCIe video card. This is a remarkable accomplishment for the new ATI RX480/RS480 chipset compared to the more mature nVidia nForce4.