what do you mean " is very bad but I'm looking for other things I can do so it operates very quickly". What are you doing on the computer when it feels like it is "very bad"? If you are talking about the computers gaming performance, I'd say your problem is not with your CPU (people are building decent gaming computers using a pentium CPU's which is slower than your i3). Your video card is very old. Equal in in performance to AMD's top card 4 GENERATIONS AGO. To give you an idea of just how slow your 6870 is compared to current cards, look at this-
The 6870 is outperformed by the 7790 by about 4%