I had oc'd sli 670's eyetrip, wf models at 1267/1228mhz cores and 7204mhz memory. My 780 isnt a great clocker tbh. Use the same settings as the sli setup, ultra, x2 msaa @1920x1200. Cant bench at the minute though as FRAPS causes bf4 to crash. But below are a few runs with the 670's.
Frames, Time (ms), Min, Max, Avg
56026, 600000, 53, 177, 93.377
Frames, Time (ms), Min, Max, Avg
75031, 600000, 49, 193, 125.052
Min fps might be up as ive always found that when moving from sli to a newer single card, but will have to wait to see if i can get FRAPS running ok to check.