3 monitor gaming desktop is not 3D. It is however a lot of resolution to power from a graphic card(s). How much money do you have to spend? You are likely looking at a new psu and at least a GTX 780Ti or R9 290X to run games at decent FPS. SLI/xfire would make it work even better provided the games you like are supporting multi gpus.
so my gtx 660 GDDR5 sli cant be use in 3 monitor?