You could throw two 7800Gt's on that and hardly see an improvement. The card you have is almost too heavy for your processor. Performance is not just about the most expensive VC (videocard), it's about having the right components. Adding a GF 6800 is like having a ferrari with one cylinder... Upgrade to a 3000 AMD 64 with a Gig of RAM and you will see an improvement. Animation is smooth as a baby buttocks on my rig and those the specs I use (with a 9800PRO) Civ is probably heavy on the processor anyway (and RAM). MANY many calculations going on, so your card is waiting for it to send something to do.