TY think the gtx 660 is going out on me so im adding the quadro to replace it i have 1 game on my pc sniper ghost warrior3 that when i send up the drone my pc will shut off this only dose it on this game only i figure something in graphic cards shaders is going bad. Ive tested my power supply it is good done stress test on processor nothing and even did one on the gp card its self not once did pc shut off but every time i run the sniper game after about 5mins or i start the drone bam pc will shut off any ideas???No you can't SLI different graphics cards. You may have difficulties getting both the Quadro and GTX drivers loaded.