I dont know what else to do, tried everything already.
My HD 7770 which is made by Gigabyte and is a Ghz edition Rev 2.0, with the latest BIOS, is underclocking on the middle of the games, it happens randomly and on several games like Planetside 2 and Guild Wars 2.
On some point the screen will flicker and the game will stop for a minute then it comes back with the lowest FPS possible because now my card is at 300/150Mhz (GPU/Memory)
I am on the latest Catalyst BETA available for Windows 8 x64
My system config Phenom II X4 firstname.lastname@example.orgGhz - AMD HD 7770 Ghz Edition - Mobo Gigabyte GA-MA78GM-S2H - Antec HCG-520