MacBook Air 2015 – CPU Frequency Limit Issue on Zorin OS

General Help
1

Hello,

I installed Zorin OS on my MacBook Air 2015, but the CPU frequency does not go above 0.49 GHz, making the system extremely slow. Interestingly, I do not experience this issue on macOS Big Sur, but as soon as I boot into Zorin OS, the CPU speed gets severely restricted.

What I Have Tried:

After extensive research, I found and installed Macfanctld. Initially, this fixed the issue, and my CPU frequency returned to normal. However, after rebooting the system a couple of times, the problem reappeared, and the program no longer helped.
My CPU temperature is around 45°C, and since the system is not using the processor at full capacity, it does not even heat up.
I ran a hardware test, and no issues were detected.

How can I remove this CPU limitation on Zorin OS? Has anyone else experienced this issue or found a solution? Any help would be greatly appreciated!

Thanks!

2

Can you try resetting the Mac System Management Controller?

  • Press and hold Shift + Control + Option (on the left side) + Power for 10 seconds.
  • Turn on the machine and boot to Zorin OS and test
3

Thank you for your support. I have tried this key combination, performed both SMC and PRAM resets, but the issue still persists.

4

Wondering if it has anything to do with Mac UEFI. I know its not an Air, just wondering:

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