I have a x1900 installed in my mac pro and want to add more monitors. I've heard there may be problems with putting a 7300 in there with it? Is it possible to run 2 x1900's? don't they need double bay PCI-e? Also how does the system allocate things to the GPU? For example I want to run an a/v performance using Ableton and VDMX running dual monitors(1 for ableton, 1 for VDMX/Module8) with dual projection. I also occassionally will want to run 1monitor with 3 projectors. Would it be possible for the system to run off the 7300 and the projectors off the x1900 giving the most power to the visuals (i'm assuming that way would give visuals the most power?)?