what is anti-aliasing?

http://en.wikipedia.org/wiki/Anti-aliasing

Pretty much running at a higher reso then you have it set to and shrinks it so it looks better.

I could be wrong, but that's always how I understood it.

basicaly it redraws portions of the scren and overlaps them so that motion looks smoother.  And you are right it is a reasource hog.

Everything looks better.

Hogs resources like mad.

Run forced AA in Diablo 2 for lulz.

These images are exactly the same where the pixels are vertical or horizontal. What anti-aliasing does is create gray regions around curves and sloped lines to give the illusion they are actually curved. This increases quality and if your computer can support it, I recommend it.

As a bonus, here's how Anisotropic filtering works:

this is exactly, right.

Thats called super sampling. The most common method used in games, usually noted as FSAA, is a blend of the edge pixels with surrounding pixels to create a smoother colour gradient. Super sampling can actualy screw up some games graphics, especialy transparent particles.

In layman's terms, anti-aliasing blurs the image to make it sharper.

Since you gentlemen are speaking about this, I am wondering, is there a way to know when you should or should not use other than say increasing the value and seeing if runs like crap or runs fine and looks better?

What other way of figureing out how to get the game looking the best vs good performance is there?

Only thing for people in general to remember is that all options arn't equal, textures rarely make a direct diffrence in the speed of frame rendering, just HD caching (jittering, loading delays, texture 'poping') and memory sizes. Detailed shadows are usually the worst performance hogging feature of a game unless your doing 16x AF and 8x AA (which is silly for 99% of people).

I would say trying stuff out is nessesary, especially since no graphics card is the same in each area of operation.

My old graphics card could do geometery FINE, could do most effects FINE. However as soon as you get layered transparancey it just hit a wall, just died. Didn't matter if it was dragonblight or grizzly hills in wow, or a hedge in velvet assassin or whatever - it hit <5 fps. Look up to the sky and 30+.

It run like crap on Nvidia graphic cards.For what ever reason Nvidia doesn't do AA good. Now Ati radeon cards runs AA much better and in some cases get performance boost when you enable AA over not having it.

Gotcha. Well I generally just let a game choose its own settings and only messed with it when i thought wow, that doesnt' seem right. AA doesn't seem to be turned on automatically so sometimes i turn it on, sometimes I don't. I didn't really understand the feature real well enough to think I should be messing with it, but if its something other people tinker with I figure I might try it when i shift to newer games again, most the games I am playing now are pretty well aged except maybe Tropico and some betas.

Nope. Antialiasing draws alot of GPU power though and you get the best results by first maxing screen resolution and then increaseing antialiasing.