You make several good points. The reality is that I did achieve basically what I was hoping to do which was run the machine full tilt OCR ing files. What I was trying to see now was whether the added instance would increase throughout. If it would, would running multiple instances on a dedicated iMac say be sufficient versus the added $ on a Mac Pro. But your question is relevant. I would like a Mac Pro but only can justify it if it would aid in the occasional large document OCR project-of which I have one now. So. I am curious about what he power of a Mac Pro will do to my apparent time of 0.8 pages per second. If it would significantly improve that then I would be tempted to get one, to crank through the documents I have and then to power a new 4k monitor for when I am reading the million pages.
So to recap. My iMac will crank 0.8 pages per second but be relatively unusable for anything else (running two instances). How does that compare to what might happen with a Mac Pro is another question. If I knew I could buy a windows machine and it would crank out files as fast or faster I guess I would consider it. But since I am my own it guy I am not inclined to service windows if I don’t have to!