I know when installing 2 graphics cards in a system it is best to use the same cards for both. I have 2 Nvidia Quadro cards that I want to put in a new system, the 4600 and the 4800. Can these two cards be connected through SLI or not? What would be the benefit? The cards would be going into an ASUS P6T7 SC workstation for video editing.
To SLI, the cards have to be the same chipset (so in your case no). Interestingly, they dont have to be the same brand. So for example an Asus GTX 280 will be able to SLI with an XFX GTX 280. Even if you could SLI, the benefit wouldn't be utterly massive.