Try removing your Catalyst Control Centre.
Had same problems as you and the CCC would leave the fan speed at 20% and let the temp go to 70degs.
Uninstall ALL amd software, then update the very latest again from amd site to get 13.251 (?) card driver and then remove CCC only NOT your gfx driver. The gfx driver itself will control the fan speed much better and I'm back to pvp fully maxed ou dx10 settings god rays etc and 200fps in hv down to 80 in the middle of jeb sag compared to 25 middle of jeb sag with CCC running the system!!!
Cards are ace but their drivers are the limiting factors
Using XFX 7990 and CCC is only really for using manual setting of overclock tbh the hardware driver already knows what to do and I hear the fan speeds go up with increased activity and its much more stable. Also if you run your sound they your audio thru HDMI to your monitor also don't remove the amd audio drivers but I would suggest using audio jack and speakers to take yet another variable away from the gfx card.
I don't know how CCC can be such a good idea but made so bad it's like permanent beta phase always clunky and limited options