Mac Pro :: Can You Run A Radeon 5770 And 5870 Together

I have a 2010 Mac Pro currently using the 5870 graphics card to run a 22� monitor. However, I am going to add a second 27� screen to my setup. I do a lot of heavy 3d modelling so GPU power is very important. I spend hours and hours panning and zooming in dense models so I would like to dedicate the 5870 power to this, rather than it running dual monitors.

I have read that you could use a GT 120 to drive extra monitors but I�ve also heard really bad reviews for its performance, making it really painful to spend an extra �120 on it. The 5770 is �80 more and has a lot more power than a GT 120.

Is it viable to use PCI Express Y-splitters to run a 5770 and 5870 together? If so how would it work? What are the dangers in doing this?

I have done some research and apparently you can use PCI Express Y-splitters to run two high-end cards on the Mac Pro, though, I couldn�t find a lot of info on the subject. I�m not really computer literate but I�m willing to do some moderate internal tinkering in order to run two decent cards (which is really surprising for a Professional computer).