Ok, so I am an avid player of day of defeat source, and counter strike source but recently my framerate has been TERRIBLE, from fps 10-30 and never is consistent and im running on fully low settings on my setup w/ the game set at dx8 . so my question is what card do i get? i want a ati card for dx11 though
The frame rates shouldn't drop from what they were on the same card... unless the card is going bad in some way. First I would try reinstalling the game and updating your drivers.
If just want a new DX11 card the HD5670 would be cheap and a pretty good upgrade over your HD4650. But really we would need to know more to make a proper recommendation. Things like your processor, psu, resolution and budget.