The grass added by turning this setting up is minimal and does not justify the loss in FPS. This setting controls the amount of grass that you can see around you. The performance hit is not significant in the cities but when you are in the woods or open fields then the performance hit is going to be much higher. You can turn this setting down to increase in-game performance. The higher the setting the more foliage you are going to see around you. This setting controls the number of trees or greenery that is rendered at any given time. You can turn this setting down if your hardware is lagging behind but you should be fine if you have a relatively decent graphics card. It is the number of elements that can be seen on the screen at any given time. The detail level is exactly what the name implies it is. This is mostly for people that are interested in playing The Witcher 3 at 1080p. This can help hide the low-quality elements of a game and aliasing. This setting adds a subtle out of focus look. This setting has a very minute impact on performance and the hit is less than a frame per second. This is an optional setting in the game that can be turned off. You can keep this setting on if you want an additional layer of realism. While recording the performance effects is not accurate, the performance hit is only a few frames per second per fight. Radial and Gaussian blur are added into the mix when Blur is turned on. These effects create distortion when in action or when casting spells.

Witcher 3 razor focus