Texture Filtering - Trilinear Optimization: If your 'Texture Filtering - Quality' setting (see above) is not set to High Quality, this option can be set to On or Off. Enabling Trilinear Optimization will result in better performance, but can reduce the quality of textures slightly. In general it is recommended that you enable Trilinear Optimization (set it to On), however if you want the highest quality graphics and/or you are experiencing texture glitches you should set this option to Off.