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View Full Version : is aa and af cpu dependant?


gram_vaz
06-18-05, 10:18 AM
i know raw fps is cpu dependant but is the performance of applying aa and af cpu dependent? or is it solely depended on the tech in the gpu card?

jolle
06-18-05, 11:18 AM
AA and AF should be done on the GPU hardware, so it shouldnt be CPU dependant really, fillrate dependant on the GPU rather..
So if your CPU bound and get say 60fps in a game, you can prolly slap on some AA and AF and still have about the same FPS, if your GPU has the legroom for it.
But the bottleneck often shifts around even inside the game, some scene your just running around, turn the corner and run into some really heavy action with smoke, explosions and stuff, alot of transparancies and whatnot that might bog down you GPU when the CPU was the bottleneck earlier.. and then you get even lower FPS with AA and AF then without again..

edit:
not sure, but there might be some CPU overhead with the drivers tho..

shockwave203
06-18-05, 03:16 PM
it's GPU. When I had my 9800pro, i couldn't use AA in the battlefield 2 demo because it would run too slow. I upgraded to an X800 XL, and am playing with 6XAA at 1280 X 960 with the same CPU. so it's placed on the graphics card, not cpu.

j0j081
06-18-05, 07:41 PM
it's GPU. When I had my 9800pro, i couldn't use AA in the battlefield 2 demo because it would run too slow. I upgraded to an X800 XL, and am playing with 6XAA at 1280 X 960 with the same CPU. so it's placed on the graphics card, not cpu.
That doesn't really prove anything. You would need to keep the same gpu and get a better cpu to test this.