Multisample Anti-Aliasing Performance
Enabling MSAAx4 saw the GTX 980 and R9 290X become almost 40% slower than they were when using FXAA. As a result, the GTX 980 averaged just 40fps and the R9 290X just 38fps at 2560x1600. In order to average 60fps plus, a pair of R9 290X or GTX 980 cards were required.
MSAA isn't really required at 3840x2160 though we wouldn't go as far as to say you don't need anti-aliasing as jaggies are still noticeable. That said, FXAA will suffice and as we just saw even with the game maxed out (minus MSAA) the game is playable using high-end GPUs.
With MSAAx4 enabled even a pair of GTX 980 or R9 290X cards can't really deliver what we consider to be perfectly playable performance.