@Szaby59: Thanks for your advice, it's indeed a viable solution. Seems work now, with acceptable performance loss(better than nothing:(). Will report back if artifacts continue.

TLDR:DC2OC 260X is broken because faulty graphic mem chip is not stable at 1750Mhz, and might crash when rapid changing mem freq.(e.g. 2D to 3D) Set mem freq to a fixed one could solve the blackout, at the same time, downclock the mem to 1600Mhz coul...