Hello,
I have a problem where my slave card in crossfire will not follow the settings of any software concerning fan speed.  I have used CCC, Sapphire TRIXX and MSI Afterburner.  I have ran out of forums to find a fix for this issue.  My Primary card adjusts fine.  Also, the slave card fan is stuck at 73-74% and can be a bit annoying at times when doing things other than gaming.  The cards work great otherwise.  The fans are near silent up to 60% in my case which is great after having Sapphire turbo jets in my ear.  
Please help me find a solution.  I have the latest drivers and have also tried previous drivers as well (cleaning with Driver Sweeper every time of course).  I have also tried a fix that I found that requires a CCC profile edit and a registry setting, which did not work.
I will be checking this site from time to time as I work randomly throughout the day.
On a quick side note, I was wondering about the "GIGABYTE VGA Smart Dust-Reducing:" mode.  Is it a feature of the GV-R685D5-1GD?  I noticed the advertising for this mode/feature on the 6850 page itself.
Thanks!