I was happy to see that a new environmental variable was introduced (COMPUTE namely) instead of the DISPLAY variable that extended desktop rendering to all adapters, therefore allowing multi-gpu usage. If one set DISPLAY, there was no way to tunnel X11 windows without the use of vnc. (I use PuTTy and XMing, or simply ssh -XC) This problem no longer exists with COMPUTE.
However if one uses COMPUTE to tell the drivers which adapters to use in association with CAL (and OpenCL), then it is possible to tunnel windows through ssh along with using multi-gpu, however aticonfig does not let overdrive commands to be issued:
"XServer needs to be running in order to issue OverDrive commands" (or something like that)
Is there any way to resolve this duality? (The long anticipated seperation of fglrx-XServer would most likely solve the issue) My only problem is there is no way to query GPU usage and temperatures this way. (It would be possible from another shell, but it's really annoying to change .bash_rc and relogin every time I want to see these infos.)