Glossary:Anisotropic filtering (AF)
Anisotropic Filtering is a type of texture filtering that makes textures that recede into the distance appear more crisp. The option to apply anti-aliasing is present is almost every PC game on the market today. In most cases, the options exists to apply anti-aliasing in levels like 2x, 4x, 8x, and occasionally 16x. This is the number of passes the anisotropic filtering algorithm makes on the current textures in the frame, and a higher number can impart noticeable performance slowdown. If you are experiencing low FPS, lowering or disabling the anisotropic filtering setting is a great way to increase performance.