So I've been playing around with a few different crossfire profiles with Star Citizen trying to get the best performance and so far 'AFR Friendly' gives the best frame-rate by far but has horrible flickering (seems like 2-3 times a second a frame will be completely black). It would be perfect if just not for the flickering but Im not sure if its a problem with my GPUs or if it affects everyone. Im playing at 2560x1440 with very high settings and with AFR Friendly I get 50-75FPS, 30-45FPS on single GPU and with Optimize 1x1 (with slightly worse frametimes too).
ASUS Maximus VII Hero Z97
G.skill Trident-X 2400 16GB (2x8GB)
2x Powercolor R9 390
Samsung 850 Evo
EVGA Supernova P2 1200W