I just got two 27" cinema displays and am trying to connect them to my Mac Pro...thought this would be pretty straight forward but something weird is happening. My Mac Pro is a 12 core and has two ATI Radeon HD 5770 video cards and running 10.8.2.
I plugged one monitor (primary) mini display port into the bottom video card and the other into the top. Both of their USBs are plugged in as well. Every time I start up my computer the monitors swap back and forth between primary and secondary. There's no rhym or reason as to why. Is there any particular order in which the cables should be plugged in (i.e. are the mini display ports supposed to be in the left or right side port hole and are the USBs suppsoed to be plugged in any particular place?)??? If I swap anything around, it changes...so I can't seem to find anything that works. Also, if I startup my computer and touch or change nothing and restart it, things are swapped around when I re-start.
Anyone have this issue or know of a solve? Do I need something else to make this run properly?