That is definitly artifacting, before you go buy a new video card update your drivers. If that doesnt work check your GPU temps and if you GPU is overlocked put it back to stock speeds. If none of that workd could be the GPU has gone bad (it happens) if it is still under warranty you could RMA it for another.
My friend had a 7900GX2 which did the same thing after one of the GPU's started going.
I just downloaded the latest drivers, GPU is using stock speeds (never OCed) and GPU temp is under 75c which is pretty normal I guess (while gaming).
Thank you, now I know for sure that I have to return it back.