How to monitor and control thermal CPU throttling in OS X?

I recently came across the Intel Extreme Tuning Utility for Windows. I tried it under Bootcamp Windows and it was very interesting to learn in what situations my MacBook Pro's (mid2012) CPU is doing thermal throttling. The tool is also designed to change the CPU's voltage, in order to reduce thermal throttling. However, this option was not available.

So my questions are:

Is there a similar tool to monitor CPU (thermal) throttling under OS X (Yosemite)? Answering this part will qualify to accept the answer ;-)
Why was the option to alter the CPU voltage not available under Bootcamp? Is this feature not supported by my CPU (i7 2.6 GHz Ivy Bridge 3720QM)?
If my CPU is capable of changing its voltage, is there a way to reduce CPU voltage in OS X?

Disclaimer: Yes, I know that this may potentially break my hardware. No warnings necessary ;-)

Solution 1:

To monitor throttling, you may run:

pmset -g thermlog

in terminal and watch output: enter image description here

If CPU_Speed_Limit is less than 100 at some moments, then it means CPU is throttled.

Solution 2:

The official Intel Power Gadget has a Mac version.

Intel Power Gadget

Solution 3:

There is an open-source menu bar app for monitoring CPU throttling (and temperature) called Hot: https://github.com/macmade/Hot/

brew install hot

It shows the information at the menu bar directly, plus a history as a line graph.

(via: https://www.idownloadblog.com/2020/11/25/hot-for-macos/)

Solution 4:

To add to Vebjorn Ljosa's answer, if you have homebrew installed you can install the Intel Power Gadget with the following command:

brew install --cask intel-power-gadget

Once installed, the app (in your Applications directory) will show you various stats.

From my limited testing, it appears that the red "REQ" line shows when the system is intentionally reducing speed/power.

enter image description here

Solution 5:

I would also like a utility to perform this function.

I don't know how to monitor this in OSX, but there is a way to reduce it: SMC Fan Control. This utility allows you to manually set your fans' speeds, which will cool the machine, reducing the throttling somewhat.