For some reason Minecraft is very slow on a couple of my Macs. It worked perfectly with Mountain Lion, 100-120FPS ++, but after Mavericks it's never been optimal.
One of the computers gets 20-30FPS with a nVidia 9800GTX Plus, but did get 120FPS before, and still gets that with Windows.
I'm testing with a Mac Pro 2008 now (2x4 core XEON), it had a 8800GT card, and I got 20-30FPS average. With a 285GTX I get 25-35FPS (max 55 when looking up/down etc).
What is going on? I only have these problems with nVidia cards and mac, other games seems to run fine.
My MBA 2011 gets better framerate than that. And my MBP 2011 with ATI gets 70-100 FPS without any problems at all.