Dishonored Gameplay on MSI Radeon HD7770 PMD1GD5

My Specs: Windows 7 Ultimate 64-Bit ASRock N68-VS3 FX AMD Athlon II X4 640 3.01GHz 4GB RAM Corsair Vengeance 1600MHz DDR3 MSI R7770 PMD1GD5 (1GB DDR5) SAMSUNG SATA III 500GB HDD With Fraps:40-45 FPS Without Fraps:45-65 FPS