Poor Performance

I'm getting lower fps than normal in the latest snapshots. In 1.7.10 I would get 170 - 200 fps max with highest settings on my desktop, but in 14w29b I get a max of 50 (and a max of 60 in 14w29a).

On my laptop in Minecraft 1.7.10 I would get a max of 40 - 45 fps on all lowest settings, but in 14w29b I get a max of 20 - 25.

(This is my first-ever bug report, so let me know if I should do anything differently!)