I'd like to request a couple of your GPUs cycles for quick experiment regarding drawing time for a massive set of points causing high overdraw. Originally I planned to evaluate the influence of the data type used for vertex attributes on drawing performance, but then I noticed a quite counterintuitive behaviour with my GTX980: Drawing time goes down as viewport vertical size increases.

https://github.com/datenwolf/pointoverdrawbench

Since the program relies on OpenGL-4.3 (due to use of a compute shader), and I ATM don't have immediate access to AMD GPUs, figures for AMD would be highly appreciated. Tomorrow at work I'll test for various NVidia GPUs between GTX680 to GTX Titan X.