BBMC Performance Guide

Post-install updates

Update your graphics configThe default options set by the game during graphic configuration aren't made for modern GPUs. You can improve quality by opening the rend_dx.ini file found in your Nascar Racing 2003 Season folder. Set the TextureSetSize value to -1. Set the AnisotropicLevel to 0.This fixes the issue of blurry textures and ensures your game will properly utilize your GPU. Set anisotropic filtering in your GPU control panel for best results.
GPU control panelOpen your NVIDIA or AMD control panel and set the texture filtering quality, anisotrophic filtering, and anti-aliasing settings to your desired quality and performance. For lower resolutions you may want a higher anti-aliasing override.
Install the 4GB patchNR2003 is limited to 2GB of RAM. Use the 4GB patch to double the RAM available to the game. This patch is required for best performance on more detailed tracks like BBMC.

Remove custom DLL filesThe d3d8.dll and d3d9.dll files (typically installed with Reshade) can improve performance by enabling new DirectX APIs. However in some cases these libraries can cause instability. Remove these files as a sanity check when diagnosing crashes or low frame rate.
Compress car filesLarge car files can cause poor performance. Make sure your car files are compressed to 2048px or lower. You can compress car files using WinMip and the car file feature.
Disable solar effectsDisabling solar effects within the game can provide a significant performance boost. It appears that modern graphics drivers aren't able to draw this effect as efficiently as in the past.
Set car detail to mediumModern mods often reduce frame rates on slower machines because of the expensive models. Lowering the car detail setting to Medium can give a significant performance boost without compromising immersion.
Reduce the number of soundsReduce the number of sounds played for additional frame rate gains.
Turn off 3D SoundDisable 3D Sound in the NR2003 settings to reduce popping, audio artifacts, and improve performance.

Keep most textures under 1024pxTextures up to 4096px x 4096px are supported but should be used sparingly. BBMC prefers to use this size only for core trackmat items like asphalt. Prefer 1024px sized mips and avoid alpha channels where possible. Textures using an invisible color are much smaller than those with an alpha channel.
Limit the number of textures per modelSandbox will stop loading 3DOs and TSDs if the number of project files becomes too great. Try to texture custom 3d objects with the fewest textures possible.
Keep polygon counts under 500Most users will have graphical artifacts and distorted models if your 3DO file exceeds 650 faces. BBMC implements a soft limit of 500 faces to improve performance and stability. Where possible, break up larger models into smaller pieces.
Create grouped objectsYou should combine objects like lights or trees to keep the number of objects in your sandbox project low. Sandbox will stop loading your objects or even your project if the number of object placements becomes too great.