I don't know anything about these but I hear if you get one it will relieve alot of stress on your primary gpu. Is this true and if so what is a good one and where can I get one?
At the moment there is no good dedicated physics processor on the market, nor is there a need for one. The only titles that support the AGEIA PhysX card barely receive any benefits, and performance is generally worse as more has to be rendered by the GPU. We'll be into Direct X10 before dedicated physics become the norm'.