Worse as in... 500fps instead of 1000fps or worse as in unplayably low? Is it locked at 60fps? Maybe you have vsync enabled?
fps are pretty unstable, sometimes i get 500 (for like 1 or 2 seconds) and sometimes it gets under 100. i just wonder that the old card works better than the new one.
and no, 100fps are not enough for pb
whats vsync?
Check graphic card drivers, if u have latest update.
i think i got every driver, there is just one more desktop driver i need.
is it possible that some old stuff from the nvidia card is blocking the new AMD?