hi there i have a 480gtx as a primary card i currently have a 280gtx as a physx card that has been fine up to now, i want to upgrade my physx card because the 280 really struggles with batman arkham city especially. so i have been looking around and have seen a 460gtx for just shy of £100.00 a 560gtx for £149.99 or a 560ti for £169.99, what i really want to know is which one is man enough to provide good performance in physx not just for now but for the future to, also which one will keep up with the 480tx and no hold it back when processing physx.
Enabling Physx gimps your frames per second and to be honest isn't worth buying a dedicated card for unless you're sli 580 GTX or something similar. Scroll to the very bottom of this page to see the kinds of fps you can expect with various dedicate physx cards:
You could always go with another 480GTX and SLI them together and use it also as a physx card, that way you will get better physx and much better fps using them together in SLI.
Not sure if its in your budget tho , but you could pick one up for approx 200p off ebay.
Just an idea.