Lulz, 4xMSAA performance is completely borked for 7970 (probably for most ATI cards).
I can run almost everything @ max (and shadows on max performance because of CPU bottleneck) and get pretty good performance even on 2560x1440. But as soon as I activate 4xMSAA with everything else at very low I get single digit numbers in the benchmark, lol (CPU is a 4770K@4.3Ghz, RAM is 32GB @ 1866Mhz and OS is Win7-64 bit). It's also astonishing that CA overlooked to add a 2xMSAA mode (especially with SSAA that would be very useful).
Btw, Shogun 2 I can run with 4xSSAA (4xMSAA + SSAA mode in CCC) @ 2560x1440 with > 20fps.
CF also doesn't really work. If enabled I just get 2x50% utiliziation. Only when I use the generic AFR (alternate frame rating) profile I get a big performance boost from 2nd GPU but then there is heavy flickering.
AMD needs to update their drivers ASAP (their last driver release is from almost 3 months ago, lol). AMDs lack in driver skills will be the main reason for me to switch back to NVIDIA for my next GPU upgrade (I pretty much alternate between AMD and NVIDIA since 10 years). AMDs GPU hardware is better value from the specs but their drivers and software pretty much suck.