Ok, I've got a client who has a HP prebuilt with a 9400gs video card. I think the psu is a 350w psu, but I'm not sure of this as I won't see the system until tonight. He wants to upgrade his video card, but he doesn't want to pay for a new power supply (despite my advice). I'm offering the 2600xt because I have a used one on hand. I also have a 8800gts 640 on hand too, but his psu will not handle it. Would a 2600xt provide any noticeable increase in frame rates?