You haven't mentioned your settings. However a phenom II cpu is not going to run the game at fullspeed all the time. Your gpu should easily be able to handle 1080p without your framerate dropping any lower but unless you upgrade to a sandy bridge cpu you should expect to see occasional drops.
"Normally if given a choice between doing something and nothing, I’d choose to do nothing. But I would do something if it helps someone else do nothing. I’d work all night if it meant nothing got done."
-Ron Swanson
"I shall be a good politician, even if it kills me. Or if it kills anyone else for that matter. "
-Mark Antony
-Ron Swanson
"I shall be a good politician, even if it kills me. Or if it kills anyone else for that matter. "
-Mark Antony