I've used cgminer 3.7.2, sgminer (latest build) and bfgminer (daily build FTP link). If I run the following scrypt:
-g 2 -I 13 -w 256 --auto-fan --thread-concurrency 8193
I get 91-92 Degrees C on each card, fans maxed out.
I have the latest Catalyst beta drivers, APP SDK 2.9 and AfterBurner running on Windows 8.1
However, if I only enable one card (i.e. in Multiminer> BFGminer), I get 760KH rate and card runs cooler at around 39-45 Degrees.
UPDATE: I removed Crossfire cable and gave more breathing room for the cards. Unfortunately temperature is still a concern and 1st GPU is now only 300-320KH
