I have an NVidia GTX 770 running driver version 344.48, and I can't get any kind of decent performance using OpenGL. If I set "Vertical sync" to "On" in the Global Settings section of the NVidia control panel, only 1 in 3 frames renders in 13ms (75fps), and the other 2 of 3 render in 26ms (37.5fps).
If I set it to any other value, even "Use the application setting", then each frame takes 3 seconds to render (0.33fps!)
What am I doing wrong? This seems like a HUGE regression from 0.4.2. Extended mode seems to work fine except for the frame rate dropping every few seconds. The odd thing is, it works perfectly on Linux, which is surprising considering how little emphasis Oculus seems to place on Linux support.