Snapshot - Unbelievable Amount of Lag

In the recent snapshot, there is an unbelievable amount of lag. In 1.6, I usually get around 60fps. In snapshot 13w36a (and b), I got around 30fps (maximized), but now I am getting between 0 and 7 fps. The game is unplayable, even with all settings turned down.

I also have noticed that the Super Secret Settings button does nothing. I've tried, the shader won't change.