yes. your cpu is the biggest bottleneck in your system. not saying you wont get an improvement by adding a gtx650ti, but some games may not see much improvement that rely on cpu power.
yes. your cpu is the biggest bottleneck in your system. not saying you wont get an improvement by adding a gtx650ti, but some games may not see much improvement that rely on cpu power.
You can overclock your cpu if you don't want to upgrade. If I'm not mistaken the E6xxx cpus could reach 4.0ghz easily, that will certainly provide a great boost in performance.
Also, I have a GTX550Ti (Rma upgrade from a 8800gt) paired with a Q6600 @ 3.2ghz and it has served me well considering I game at 1680x1050 resolution. You'll be able to play all the games you like easily at that resolution (1600 x 900), even if a bottleneck exist with your CPU. Some people use the term bottleneck as if it makes the game incapable of running at all.