Originally Posted by Lord Xeb
There is no way to force it into permaboost mode unfortunately. Even with my cards the way they are, I don't boost all the time. Boost is controlled by the firmware on the card itself and many factors play role from power draw, heat, core load, voltage, etc. It is built right into the GPU so there is no way to alter that. Just stick with what you have and you will be fine. For what it is, the 680MX is a fantastic card. If you want to overclock or get better performance for gaming, you should not have bought a mac to begin with.
Let me re-iterate here: LEAVE IT BE!
Xeb is 100% right.
Apple spends millions on R&D to foster the most stable environment they can for users in both hardware and a software.
This is achieved by re-tuning hardware and locking the system down in various ways
Buying a mac and trying to really play with its hardware or low level stuff is a waste of money and energy.
Just enjoy a stable computer, thats why you pay so much extra.
(Well, that and the brand)