You're all half right. Generally, you cannot run triple display in SLi, but technology is so great these days. You can pretty much buy anything to modify anything else. Such as with the
Matrox TripleHead2Go device, which allows you to run three (3) displays in SLi or Crossfire. The device either allows you to work with three independent monitors, but why do this when you can disable SLi, or integrates the three displays into one gigantic desktop. The SLi is important because, depending upon the size of your screens, you will have an
insane display resolution of 4080 x 768 (if your display is: 3 x 1360 x 768) which will need a lot of GPU muscle to run games at high settings. So, if this seems like an option for you: READ the device specs to make sure your native resolutions are supported.
It's a pretty sweet device that comes in three flavors: analog (VGA); digital (DVI); and a third that throws in some unnecessary features. The only hitch to this plan, other than your monthly electric bills is the up front cost of $300. But, if you're using three displays already, you're probably not going to break the bank to add this feature...
And, because I think it's a terrific item, I would add the triple monitor stand from
Ergotron. This allows for great cable management and display orientation. This particular model allows you to rotate your displays 90 degrees for portrait views (in the case you're a photoshop guru or hate scrolling). This, of course, is only useful when your displays are independent of one another...