.NET automaticity gives the graphical load to the GPU rather than CPU and its locked, however light it may be. So GPU(s) only, the driver then fires up all GPUs for .NET frameworks with 0 load on any other card ever. Something needs to be done in the driver to handle or deal with .NET frameworks elements better, it shouldn't be waking every GPU causing the case fans to start etc.
Windows 8, 7950 + 7950: spotted GPU1 fan always on, pin pointed the trigger as a start-up program.
8.1 same, 7990 + 7950: Anything that uses .NET, and a few random GPU waking things.
10 same. 7990: same (last 5 iClouds, Raptr, Aquasuite, Sound Blaster Control Panel, Logitech Gaming Software. All .NET .
I don't know if this is an isolated issue or that people just haven't noticed their slave GPU running. If this .NET thing does the same to you let us know, if you have the time I would be grateful if you could run a problem program and check your slave CrossFire GPUs' status'. ( ' goes somewhere, tired).
My understanding is this can be sorted if addressed within the driver, I don't even know if its worth reporting (I'm sure I have). I could be wrong and there is a very good or simple reason why this happens. I'm happy to try a few things is anyone has suggestions or needs more info. Thanks