I am currently having a problem on my Macbook. I run minecraft on pure vanilla. Apparently, Minecraft 1.5.2 only works best on the OLD launcher. I am able to run the game on 30-60 FPS. But when I switch to the NEW launcher, it drops down to around 8-10 FPS. This is also evident with Minecraft 1.6.2 how can I fix this? I already tried updating my Java 7, I have already tried to set javaw.exe to high priority over at the task manager, I have also tried fixing the java arguments switching memory from 1024 to 512 to 320, I don't seem to get changes.