I came across such a problem 4 months ago, I bought this vidyukhu and there were staters in the games and the GPU frequency jumps then 1500,800,2000 and is accompanied by friezes. I wrote it off to raw software. Downloading new versions of the driver did not help If you fix the frequency in Adrenaline, then everything seems to work, but after 10-20 minutes a black screen appears and an unexpected error Radeon wattman writes in the software. Demolishing Windows also did not help. Used MSI Afterburner 0 effect. A friend of 6600 che has everything ok. Is this even a warranty case ?