Originally Posted by bob saget
Another question: would a 3gig GTX 580 give me significant improvement over the 1.5gig version at 1920x1200 for mainly BF3? And also, would the increased memory allow me to enable higher Physx settings in games that support this feature.
You'd have to check your VRAM usage while gaming (I use EVGA Precision for that, but Riva or another tool should be able to do it ). Right now I'll tell you the answer is maybe for 1920x1200. On the Back to Karkand maps I see VRAM usage (at 2560x1600 with all in game settings at Ultra) run between 2.1 GB and 2.7 GB (Skyrim with a boatload of texture mods will do the same thing). My old 1.5GB cards would have a lot of swapping/thrashing going on has they switched out textures, causing frame rates to regularly dive below 20 FPS and eventually BF3 would crash (I had to pull back the AA settings to get it to fit in VRAM). With my current 3GB cards BF3 is smooth as silk and can run all day.
I'm not sure about the Physx. And outside of Skyrim and BF3, nothing else I play really takes advantage of the extra VRAM. You might want to post in the BF3 thread to get so comments on 1920x1200 VRAM usage, since it looks like you're coming from a Radeon by your sig.