Sad sam vidio da 4850 ne podrzava riva tuner. Procitao sam ovo na jednom forumun mozda ti pomogne, ja nisam isprobao tak da neznam dal radi
if you make a profile in catalyst after turning on Overdrive( make sure clock and memory settings are correct). You can then go to the file "C:\Users\Bretware\AppData\Local\ATI\ACE\Bretware. XML. the xml file will have the same name as the catalyst profile you saved. right click and hit edit.
<Feature name="FanSpeedAlgorithm_0">
<Property name="FanSpeedAlgorithm" value="Manual" />
</Feature>
<Feature name="FanSpeedRPMTarget_0">
<Property name="Want" value="0" />
</Feature>
<Feature name="FanSpeedPercentTarget_0">
<Property name="Want" value="65" />
Change the value to "manual" and Want value to "65"
Save the file then reload your profile in catalyst.
65% seemed perfect for me, 70% was loud but you may need it if your case has poor air flow.
You will may have to select the profile everytime you start the computer, but it will work until there is a fix or better info so i can figure how to change the auto target temp.