Get MSI afterburner or something else that will monitor and log your clocks while you are in a 3d application. Just because you are seeing 157 in CCC doesn't mean that's what your card runs at in games. And what exactly to you mean by "3d problems in games"? Are the games running but laggin badly, video tearing, textures missing? Does it crash? In what games at what settings? And the really helpful people here are going to require you to post your complete system specs/os/driver versions ect. before they are going to be able to help you test and declare your video card bad or not.