What was the key to get CF scaling to work for you? Was it Skyrim 1.2, or the "CrossFire dll for 4gb fix ". Can you link this please?
I am not using any 4gb fix as I never had ctd.
Try just going ahead and using the 4gb Fix as well, just to see what's going on since I'm now using modded dlls. Even if you didn't use it before, try it:
11.11b drivers
4gb Skyrim: http://www.skyrimnexus.com/downloads/file.php?id=1013 (put the exe and dll inside your Skyrim folder where tesv.exe is)
4gb Skyrim Crossfire: http://www.skyrimnexus.com/downloads/file.php?id=2182 (put this dll inside the Skyrim folder where tesv.exe is)
Launch Steam > Launch Hayden 0.7 and 'Inject' > Launch skyrim4gb.exe
This is somehow working great for me. I wasn't seeing anything too different when I first started on 11.11b without the 4gb patch, but I was getting bad CTD. With the 4gb patch, I lost crossfire scaling. With all the stuff I listed, it's now working quite great. I still seem to get a few odd hickups in dungeons, but not bad. Otherwise I'm seeing much higher framerates than single gpu and 99% usage on each GPU watching them in GPU-Z.