Win11 on Macbook with M1 Pro = 2 Ghz CPU in Windows

[Patrick Gehlich]

Hey there,

i tested Parallels and Fusion.
Would like to go with Fusion, But why does Windows 11 CPU in Fusion just shows 2 GHz for the CPU?
I added 8 cores.

Parallels shows the full 3,2 ghz in the windows Task manager.

Thank you :)

[Technogeezer]

No need to worry about what's reported. It's not relevant.

TL;DR

macOS runs each virtual core as a thread on the host. macOS controls the core frequency of the CPUs used by the threads, not the guest. macOS could change frequencies up or down at any time based on system load (yes, it is also theoretically possible that macOS could use an e-core for the VM if CPU demands get sufficiently oversubscribed) and thermal throttling -- and the guest wouldn't have any idea.

As to why the guest is reporting 2GHz, only Broadcom can say. But as I said, it's meaningless in any case (for both Parallels and Fusion).

It's possible that reported value is arbitrarily set by Fusion (and Parallels). From some research (and this article by Howard Oakley https://eclecticlight.co/2025/01/20/what-are-cpu-core-frequencies-in-apple-silicon-macs/) it's also possible that the reported value is related to the max e-core frequency (which on your M1 Mac might be in the 2GHz range). However, you'll find through Activity Monitor that the VM is very likely running on the P cores - which have higher frequencies.  

If you're really concerned about the CPU frequencies being used by the VM, the only way you're going to get that is to use some of Apple's development tools such as powermetrics. top and ps won't work, and Activity Monitor can only tell you the utilization of performance and efficiency cores - not the CPU frequency.

 I've personally never seen the reported CPU frequency in Windows 11 guests as an issue.

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- Paul (technogeezer)
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