Just a heads up OP swtor doesn't support SLI, you need to create your own profile to combat the lag. And just saying, 3 980's is extreme overkill for this DX9 game unless you are running on a 4k monitor. Run the game with 1 card, use fullscreen windowed and make sure you are running the client as an administrator.
EDIT:
This was recorded on a rig with x1 GTX 760 4GB at stabilizing at 50+ fps. You really dont' need much to play this game.
(my cpu is i7-4790 @3.6)
EDIT (2): OP I just noticed you have 12gb vram, are you running this game on 3 monitors?