http://www.anandtech.com/show/7930/the-amd-radeon-r9-295x2-review/16
Interesting look at the AMD R9 295x (a dual GPU version of the R9 290x) This review indicates that Vegas does not support multi GPU configurations. Now this does not mean that there is no benefit from separate video cards for each monitor. This sort of answers my question, as I have been wondering if adding more cards to the OpenCL puzzle would help. OpenCL should use multiple cards, but apparently it is not as seamless as say HyperThreading. I wonder if this is just a AMD driver issue or a Vegas issue? There were other tests that seemed to show the same single GPU results, which leads me to think this might be am AMD driver issue.
Anyone else have any thoughts?