I do not believe Maya can utilize SLI or more than one video card. This might be different with Maya 2016 as in that release it has apparently become multi-threaded and can utilize video cards and entire CPU for viewport playback. That being said my logic behind having 3 980 cards (probably overkill… two would of been plenty) is to have one card running Maya viewport and another to be running Vray RT.
One of the issues I realized after getting the rig at work is that I cannot figure out how to delegate what card Maya uses (unlike Vray RT where you can specify, but this really doesn’t do me any good because I don’t know which card Maya it utilizing). I need to do more research.
On a side note, switching to DirectX the Maya settings for viewport cleaned my issue, but isn’t something I can work in all the time since for whatever reason Vray materials don’t preview in the viewport when running DirectX. I would think this would be a basic functionality inside of Vray to be compatible with DirectX in Maya’s viewport. Even though Maya has been developed around OpenGL (unless I’m thinking of OpenCL that it was developed around).
Anyway, things seem to be stable as of now and I can run Maya and Premiere side by side as long as Maya is in directX mode (in Maya). This is nice because I really enjoy creating playblasts and editing them into a rough cut right away so I can figure out what my camera’s need to be doing and get direct feedback as to how the look and feel of the animation in the production is going.