Just adding this in case someone has the same problem.
I was having a very high performance decrease when playing youtube videos in full screen. Video became choppy. Seems like there is some kind of problem with flash 11. It helped a little bit if I disabled hardware accel, but not enough.
I run Maya 64 with the Intel 965GM Driver
I replaced mint-flashplugin-11 with
Now it seems to work fine.
Custom build w/ Gigabyte Z87MX-D3h | Intel Core i5 4670 | 8GB DD3 | 250GB SSD