Texture Anisotropic settings?

What exactley do they do? I turned it to 2x and I noticed a significant framerate drop.

Whats the difference between it and antialiasing?

Is it Anisotropic Filtering?

Anisotropic filtering filters textures to make the depth blur look cleaner and clearer from any angle. Antialiasing smooths out the edges of polygons, resulting in a cleaner appearance of the shape. They do entirely different things...

So do most poeple use Anisotropic filtering?

I don't generally because when I'm playing a game that's the last thing I could care about...with a few exceptions, one being Morrowind. I turn it on when I play that because your outside for most of the game, and the depth blur of the textures is greatly improved. It's just personal preference, really. I hardly ever play with AA on...too much of a performance hit on my machine for me, and I could care less about jaggies...

I turned on AA 2x and I still notice jaggies..... I may just turn it off to get more fps back.