Haven't we had a thread in the backroom about good and not so good graphic cards? Maybe you look there too. BTW, 3 million polygons does not seem to be a big scene to me. Mine are normally between 10 and 50 million. And i have not too many problems with OpenGL. What i do to handle things is to make things i don't need anymore for the moment invisible (put them on different layers and...). Or select Wireframe box as display mode for complex objects i have positioned finally. Helps a lot.

One day your ship comes in - but you're at the airport.