HD4870x2 Working fan speed in here.

[DeusGear]

Hey guys I installed expert tool v4.0 (that supports hd4x line) and to my surprise it controls fan speed of the hd4870x2 as well!
http://en.expreview.com/2008/08/16/tools-update-experttool-v40-enable-fan-control-on-hd-48504870/
I gotta say though at 50% fan speed my idle temps dropped from 67c to 36. However at 50% speed I can't believe how amazingly loud it is. GTX280 at 80% fan speed sounded quieter then hd4870x2 at 50%!! At 100% my idle dropped to 26c but jesus christ it completely drowns out my Air Conditioner in sound!
Stock 27% fan speed = 1300 rpm
50% fan speed = 3230 rpm
100% fan speed = 4920 rpm.

[Xion X2]

ATI's fans move a lot more air; that's why they're louder. 36 idle is pretty damn good for that card.

[K007]

i guess you just have to play with the fan speed.

[Nar]

http://forums.guru3d.com/showthread.php?t=270486

Download link is there...

Fan speed, overclocking! (nana2)

[DeusGear]

http://forums.guru3d.com/showthread.php?t=270486

Download link is there...

Fan speed, overclocking! (nana2)
Doesn't work on hd4870x2 so it's kinda pointless for this thread.

[Heinz68]

I download the Gainward ExpertTool ATI v4 at Expreview (http://en.expreview.com/2008/08/16/tools-update-experttool-v40-enable-fan-control-on-hd-48504870/)
Basically the Fan Control works works the same as the Profile Fan-Control Hack (http://www.nvnews.net/vbulletin/showthread.php?t=115569). I had only the main profile set (not named ones) and the ExpertTool ATI is changing the profile on go, as set.

Here the Fan Control set on Dynamic Speed (Auto), nice idle temp at 16% fan speed (not O/C). The fan started at 27% but went down, I guess due to the low temp. Who said the 4870 runs hot.
http://img103.imageshack.us/img103/3856/fancontrolip7.jpg

Here at the Fixed Speed setting. The minimum settings is 50%, some people think it's a bug. I believe it was set purposelessly at higher speed for safety reasons since the auto is disabled.
http://img515.imageshack.us/img515/9881/fancontrol2so8.jpg

The ExpertTool resides in the Tool Bar and when clicked on here are the other options.
http://img116.imageshack.us/img116/8585/expertoolatiop3.jpg