Please help me, I want change my vga with new one (AMD Radeon) My specs : AMD phenom II x6 1090T 3.2Ghz Ram 8Gb Windows 7 3-bit AMD Radeon HD5500 I better change Radeon R7 or R9? and which type? I like R7 250 iCooler 2Gb DDR5. What do you think? its suitable? or not optimal. Thank You.