OSX able to throttle down CPU on heavy usage?

Solution 1:

You may want to run Software Update. It could be that you're missing a SMC update, which addresses freezing at (continuous) high CPU loads:

MacBook Pro SMC Firmware Update 1.5

Or this EFI update:

Macbook Pro EFI Firmware Update 2.3

Solution 2:

The best action to take is to ensure you are not giving the CPU work to do. When you throttle a CPU in hardware it slows down everything, and what seems simple in practice "slow down the bad stuff" gets incredibly complicated and not so effective in practice.

Crashing and freezing of the OS are fairly serious unintended behaviors, so that should be your first priority in isolating. Have you looked into the Console app to see if there are system panic logs getting created or if you will instead need to profile the system to see what is happening when the freezes and crashes are in process.

As an analogy - you're looking to tune your running stride to go from a 2:25 marathon to a 2:20 marathon at the same time as you have a sprained ankle and perhaps a broken knee. Fix the big problem before you try to tweak a small one. Small doesn't matter when the house is on fire - and system totally freezing is your software saying your system is on fire and needs attention.