Depending on the model of the video card you have, these features could have either a positive or negative impact on gameplay performance and image quality. If you feel you are experiencing sluggish system performance with these features on, it is best to disable them to ensure optimum gaming performance. When proceeding higher then 4x AA or ASF, this is where you will notice the performance hits. Please note, there are other variables within a users system that will also hinder game performance when enabling these options.
Below are explanations on each possible option a particular video card may have. Please note, not all video card models may have all of the below options.
In the above image you will see settings for; Image Settings Quality, Anti-Aliasing and Anisotropic Filtering.
Image Quality - If you wish to turn Anti-Aliasing and Anisotropic-Filtering on, you may want to consider setting this option to "performance" or "high performance" for the best gaming experience results.
Anti-Aliasing - Aliasing is the jagged edges on curves and diagonal lines in a bitmap image. Anti-aliasing is the process of smoothing out those jagged edges. Another term commonly used is font smoothing. Without anti-aliasing, diagonal edges appear jagged, like staircases, which may be noticeable on a low resolution display. The default for this setting is "Application Preference". Increasing this setting to 2x or more may improve overall image quality while having the possibility of degrading gaming performance.
Anisotrophic filtering - Anisotrophic filtering makes it easier for the viewer to see the quality of textures on surfaces at greater angles. If you are using an older video card and have Anisotrophic filtering enabled, you may take a huge performance hit. The default for this setting is "Application Preference". Increasing this setting to 2x or more may improve overall image quality at a distance while having the possibility of degrading gaming performance.
Please note, by increasing or turning on any of the above options may result in system instability. If you experience any graphical corruption or anomolies it is advised to turn Anti-Aliasing off and see if the problem persists.