your geforce 210 is the problem ... this isnt designed for gaming and with its inferior 64bit memory interface and low core/memory clocks its bottlenecking the system pretty bad .... a good sub £100 gpu upgrade would be the excellent GTX750 ... low power draw and outstanding performance and when combined with the i5 3330 you will be able to run cod ghosts and assassins creed ( all titles ) at medium to high detail ( medium at 1080p ) .... on the AMD side of things the R7 260X is worth considering and this supports mantle