LoopFX --motion designer--

I hope u guys can help me i have alienware aurora with: processor: Intel Xeon W3570 3.20 Ghz graphic driver: Amd radeon R9 280 Ram: 12 Gt and 64-bit, still my games are laggy and i can record assassins creed 3 like 60fps but when it comes to minecraft my fps drops sooo much it's like 10-40 and it's too laggy for making montages and i thought if u could help me somehow