CPU is almost 10 years old, and at 3.2 it's quite low clocked for what is considered normal these days. It is definitely the weak link in that system.
Q6600 won't be much better either to be honest, I had that back in the day (was a fantastic chip back then) with a 560Ti and it was bottlenecking it in a lot of games.
Time to upgrade and get a new mobo+cpu op![]()