A couple weeks ago I set out to do a project where a scene of millions of objects could be rendered fast using OpenGL and OpenCL performing frustum culling. This is a screenshot of a fraction of the world: only 169,112 out of 20,000,000 instances are drawn.
Tonight I decided to expand this project to include Order Independent Transparency. The program is the same as before, but every object now has an alpha of 0.5. Click the image to see it in full detail.
As I expected, the frame rate went WAY down. Before transparency I had roughly 118 fps, and now with transparency it's at 33 fps. Though I may not ever achieve 60 fps, I believe that it is possible and I will try to do it.
(Edit - added a better picture)