nVidia

GeForceX video card tweaking

(Dec 2, 2002)

A tweak guide from 3dspotlight. Covers issues like AGP settings, AntiAliasing settings, texture filtering, and some D3D and OpenGL settings. Some of these are exposed by the nv driver, others can be set by using the NVMax utility. Linux users can look at my Linux tips for instructions on changing the AGP settings.

My main concern was looking to tweak the AGP settings for optimal bus bandwidth usage (example applications : immediate mode rendering, texture paging etc...). The 2 related settings are Fast Writes (FW) and Side-Band-Addressing (SBA). More details on AGP speed and FW performance on Toms Hardware.

FW sends data directly from CPU to GPU without using the system DRAM as a bridge. Ideally this should improve performance (as reported by an nvidia whitepaper), but actual test results for 3d gaming benchmarks have shown no improvement (or even a decrease in performance - the tests are with a GF2, and probably older drivers). If the geometry is already in system memory and the CPU merely tells the GPU to render it from the system memory locations, then I doubt it would increase performance. However, what about applications where the geometry is computed dynamically on the CPU, or parameters to vertex/fragment programs? The whitepaper mentions improvements for loading D3D textures, what about OpenGL texture loads? Let me know if you have further comments/benchmarks on this.
SBA allows 8 more address lines to be used in addition to the existing 32 lines for address requests. This should improve performance, but I could not find any benchmarks on this.

Note : Setting above options can cause system instability, so make sure to get latest chipset drivers and patches.