How should I interpret this CPU usage information on Parallels from Activity Monitor?

G

GerbenW

Member
Here is a view of macOS Sierra Activity Monitor, just after having started a Windows 10 VM in Parallels and it is busy.

(Hmm, I can't upload a screen shot, can I? Oh well, I'll describe.)

Activity Monitor (My Processes) shows that the Windows 10 VM process is taking 198.1%. Sometimes it even shoots to 210%. This is on a 2 core CPU and the VM has been set to use 2 processors.
But on the bottom, the overall CPU load says the system is 42% Idle.

So, how does one interpret these figures?
 
Yes, this is on a 2 core Core i5 in a MacBook Pro Late 2013 (with 8GB RAM).

Note everything works fine (expect that it hasn't been possible to get Full Screen VM on a second monitor on any of my systems, but that is in another unresolved and dead thread on this forum, still waiting for a resolution on that one)
 
GerbenW said:
the VM has been set to use 2 processors.
Click to expand...
Thanks for the details. In this case, the VM should definitely use only 1 processor core (Mac must be allowed 1 for itself when the VM runs, else it'd suffer from performance load). Please set the number of cores for the VM as '1' and revert with the results.
 
There no problem with a setup like this. Going to a single core is not necessary, after all the OS is a time-sharing system and as long as we do not overburden the system it works fine. You can compare it with running multiple apps. As I said, Parallels works fine. And I recall that I once tried running with 1 core for the VM (with the same idea behind it) and Windows ran terribly slow on one (virtual) core. Very interesting, I ask one thing and I get unnecessary (and probably wrong) advise on another thing solving a problem I do not have.

I think we are now moving away from my original question. I was just wondering about what Activity Monitor reports.

Maybe it's better if I tell you I see the same on a 4-core iMac with a VM that uses 2 of the cores.

G
 
GerbenW said:
There no problem with a setup like this. Going to a single core is not necessary, after all the OS is a time-sharing system and as long as we do not overburden the system it works fine.
Click to expand...
The resources allocated to a VM are locked with the VM as long as it runs. Assigning 2 cores to a VM running on a 2-core processor system means you're depriving your Mac of its processor resources. This certainly puts immense strain on your Mac hardware - a fact that won't change just because you assume it's alright to allocate just about all of the available cores to the VM.
GerbenW said:
Very interesting, I ask one thing and I get unnecessary (and probably wrong) advise on another thing solving a problem I do not have.

I think we are now moving away from my original question.
Click to expand...
No need to make pointless presumptions here. Moving away from your original question wasn't the intent; it was rather to provide answers along with stating the implications of the given setup. Hence the reason for asking you to change the setup so we could have observed how the numbers would look like this time.
GerbenW said:
Maybe it's better if I tell you I see the same on a 4-core iMac with a VM that uses 2 of the cores.
Click to expand...
Right to the answers then: If the VM has 2 cores allocated to it, multiply this number by 100%. So the VM's total consumption on Mac will equal 200%. Meaning, the VM's CPU consumption in Activity Monitor is normal if its consumption value is shown to be below 200% (it's again normal if the consumption value goes beyond 200% infrequently). Pls see this article for more details.
 
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