Hi , since i dont have the money to build a new pc right now in about to upgrade my existing one [for gaming]. My current specs are , amd athlon II x4 750k 3.4ghz , 10gb ddr3 ram , saphire radeon 7770 oc edition 1gb gddr5 , asrock am55 something like this. What part shud i upgrade first ? Thx for the help