My monitor is plugged into my amd card via dvi. So far as long as my gtx1070 is plugged into my mobo it seems to be my main display device even though it is not plugged into my monitor. If i unplug the gtx1070 from the mother bored the other card works fine while in the pciex4 slot. Is there a way to force my amd card to be the one my system uses by default. maybe this is a linux question.