CougTek
Hairy Aussie
Two of the last three Radon HD 68xx I've bought for customers needed replacement from the get-go. No DOA, but stability issues. One had its driver constantly fail in Windows 7 and the other one refused to play nice with Adobe Flash (needed to disable hardware acceleration) and sometimes drops lines at random moments just showing the desktop. None of them overheated and both were powered by a 700W decent power supply (two completely different systems). One was from Sapphire (Radeon HD 6870) and the second one was from Power Color. I don't think the card manufacturer is responsible. The instability seems to come from the GPU manufacturer which ships plain defective chips.