I'm glad to see ATI doing so well with its new cards. I just got an HD 4850 and tested it with the excellent "Crysis Benchmark" bat file. This ran smoothly at a variety of video settings.

Then I installed this new ATI driver "Hotfix", hoping for better cooling fan control and perhaps increased speed. However, this CREATED PROBLEMS. Now the Crysis Benchmark stutters badly, sometimes stopping for several seconds before continuing.

Since the benchmark merely runs the game itself, I'd expect to see the same issues there. I returned to the Catalyst drivers that came with the HD 4850, and the original smooth performance is back.

This is on a 3.8GHz QX9650 4GB WinXP system with plenty of fast HD space.

http://techreport.com/forums/viewtopic.php?f=3&t=59864

In the post near the bottom of the first page, I explained the idle temps as I understand them. I'm thinking of contacting an AMD employee and begging contact info of someone in engineering to confirm/deny.

Yeah, when the difference between idle and load is 4 degrees, either the cooling is awesome or terrible. 78 idle, 82 load in my 4850. The fan just never spins up over 30%, and there's no way to control it as of yet.

The high idle just goes against what I've heard from AMD. They were telling me earlier in the year to expect < 3850 idle power for the GPU. So unless these boards are badly done (unlikely) or the ram has very high power requirements AMD still has a trick up their sleeves.

Can you please test and see if it effects the idle power consumption

They do include support for the HD audio, and no, they do not lower the idle temps. You just install the hotfix like a regular video driver, plus it has the CCC as well. Installed without issue.

I got 'em, they also seem to include support for the HDMI audio chip, which the 8.6's don't.