SLI-AA Performance: FarCry
Recalling what was explained to us by NVIDIA regarding potential performance advantages of the company's new chipset in SLI-AA scenarios, we set out to prove the theory ourselves. Below are tests with the 1.33 version of Far Cry with SLI-AA 8X and 16X modes enabled at 1280X1024 resolution. We compared frame rates of the new ASUS A8N32 SLI Deluxe nForce 4 SLI X16-based motherboard versus the legacy ASUS A8N SLI Deluxe nForce 4 SLI standard board.
** Article Updated 11/11/05 - BIOS Incompatibility Found **
When our article first launched on 10/18/05, we reported to you our findings based on the hardware and related driver versions we had in hand at the time. Unfortunately the Asus A8N SLI Deluxe motherboard we tested in comparison to the A8N32 SLI Deluxe, needed a new BIOS update to take advantage of NVIDIA's recently released 6.82 nForce chipset driver. This driver version was released in support of the nForce 4 SLI X16 chipset and we came to find out that the legacy A8N SLI Deluxe had performance issues with this new driver. Asus sent an updated BIOS for the A8N SLI Deluxe to us on 11/2 and we had to re-run our numbers in order to confirm our initial performance findings between the two motherboards. Here is what Asus reported to us with this BIOS release...
" A8N-SLI Deluxe 1015.006 --> Support the NVIDIA 81.82 graphics driver and nForce 6.82 driver to increase X16 performance. "
At the time we were testing with the 1013 version of the A8N SLI Deluxe BIOS. Our first pass benchmark findings can still be seen here but clearly they are erroneous due to the fact that the A8N SLI Deluxe's performance was hampered by this chipset/BIOS incompatibility. The following are our updated SLI-AA benchmarks with Far Cry.
Obviously, we do not see the 55 - 65% performance advantage we initially reported back on 10/18/05, for the A8N32 SLI Deluxe and NVIDIA's new nForce 4 SLI X16 chipset. In reality, there is a more modest 5 - 15% performance gain over the X8 SLI setup on the A8N SLI Deluxe, due to increased bandwidth for inter-GPU communications during frame blending operations.