Toms Hardware has a post about problems with various boards using amd/ati chips HD4000 and HD5000 series. At this time there is also 6 pages of comments which suggest problem might be: production problems, thermal problems, windows driver problems, etc.
If it's a Windows driver problem, then linux shouldn't be impacted.
Looks like someone at nvidia is pulling up some panic about ati cards
I cut&paste doron's comment:
Originally Posted by Doron
As a regular visitor in the amd forums there are dozens of problems posted every day, usually made by average people who just assumes a certain part of their computer for causing this problem without a thorough check, which sometimes proves to be incorrect.
Consequently, I think that's something like a chicken / egg dilemma, since when people who have problems with their computer (underpowered psu, bad memory etc.) visit some forums and see huge stickies with 5xxx problems, some of them conclude that the gpu is at fault and add something of their own to the thread.
We should put these problems in prespective - The fact that 2 million cards were sold in a relatively short time and that the **official** amd forum has only 30-40 people who are crying for help and is not flooded with hordes of people is a good sign.
As a side note, although I do own an amd cpu + gpu, I'm not a fanboy and do not appreciate anyone who's commited to any company (i.e. fanboyism).
I own a hd4830 and a mobile hd3450 and never saw gray screen except installing catalyst 9.12 from fedora 11 repos, but the cursor and the system were perfectly responsive.