Http://www tomshardware com/forum/291058-33-hd4870-dying-wierd-artefacts-boot

[Fujimoto]

Hello,
Flashing Screen in Certain games only have a HD 4850 1g XFX any time i try to run FFXIV retail or the Benchmark the screen starts flashing from the menu and is unplayable in game have a BE 555 4 core at 3.7ghz 4 gigs of 1600 ram 700 PS and a ASUS M4A89GTD MB pls help me idk if my Card is teh issues the drivers witch i have 10.9 or what to do?!

 

[wa1]

what about the other games?
Does it flashing as well?
Then try use older driver like 10.3 or 10.4, see if that help since that's the most stable driver for now..