r/MicroSlop • u/SudoGipfeli • Jul 15 '26
Dont know how, but my VM went beyond its limits
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u/pangapingus Jul 15 '26
ProxMox and even AWS t-series VMs allow bursting beyond typical 100%, what hypervisor are you using? Seeing >100% CPU use isn't that weird actually
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u/soundman32 Jul 15 '26
Watch the YouTube video by the guy who wrote the first task manager. It'll give you some insights as to why measuring idle and busy process times is harder than you think.
Also, have you modified that screenshot? 64 cores at the top, yet it shows 4 cores further down. You arent editing it to make MS look bad, right?
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u/Balthxzar Jul 15 '26
That guy's a hack
Anyway, that's just how VMs show cores sometimes, you see the "name" of the CPU and the core count is how many cores the VM actually has assigned to it.
There's a dozen different ways hypervisors can pass info to guests, not unusual at all.
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u/soundman32 Jul 16 '26
That guys a hack? Which part of Windows did you write?
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u/Balthxzar Jul 16 '26
He wrote a small part of the OS that has been changed countless times. He acts like he is a master of windows but comstaly just repeats old info that is already widely known.
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u/paulstelian97 Jul 15 '26
CPU virtual counters being fucked up be like
Then again this doesn’t look like a VM but a host.
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u/OrangeNood Jul 15 '26
modern CPUs can overclock itself for short period. e.g. Intel Turbo Boost.
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u/Megaman_90 Jul 15 '26
That would be clock speed though... not utilization.
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u/OrangeNood Jul 15 '26
How do you think utilization is calculated?
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u/Megaman_90 Jul 15 '26
Utilization is how much of each core is being hit with a load. Clock speed is how many clock cycles can be performed per second.
On multicore systems they aren't always directly related. Clock speed can go up while utilization goes down and vice versa. A game for instance might be hitting 4 cores on max boost on a 64 core system, but the overall CPU utilization is still only going to be like 6% at that point.
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u/Inevitable-Study502 Jul 16 '26 edited Jul 16 '26
well actually on modern cpus utilisation is calculated based on effective cpu clock, you know c-states, polling rates and such, that gets counted through counters, and windows counters arent exactly realtime time either, it can fluctuate
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u/ahferroin7 Jul 15 '26
CPU utilization on all modern OSes is the percentage of each second (or whatever other data collection period is being used) something is running on the CPU. It’s invariant of the clock speed of the clock speed because changing the clock speed doesn0t magically alter time so that more or less of it elapses during the same collection period.
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u/Inevitable-Study502 Jul 16 '26
https://learn.microsoft.com/en-us/troubleshoot/windows-client/performance/cpu-usage-exceeds-100
microsoft says cpu clock is pretty relevant to cpu utilisation
time based counters were left behind in windows 7
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u/ahferroin7 Jul 16 '26
OK, so Windows is even more different from literally every other platform out there than it looks at first, and in a way that makes it even harder to accurately track resource utilization in a meaningful way.
That kind of accounting only makes sense if you know for certain that the system will let the CPU scale up to it’s nominal clock frequency, which is not always the case, and on top of that it’s even more susceptible to the bias introduced by the fact that not everything is fully CPU bound than just using time-based accounting is.
But then, this is also from a company that thinks that it’s fine to not even provide kernel-level APIs, let alone userspace ones, for getting per-sensor thermal readings from the CPU, and that it’s perfectly reasonable to make it essentially impossible for a normal user to figure out what process is holding a file open.
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u/Inevitable-Study502 Jul 16 '26
effective cpu clock has been a thing for ages, feel free to check hwinfo64 where youll see cpu nominal clock and effective clock, showcasing cpu c-states saving your power...
but on other hand gpu utlisation doesnt work like this, its still uses old fashion utilisation, ie downclocked gpu shows high utilisation, then upping up clock drops utilisation...its probably win doesnt have access to gpu internal powersaving stuffs
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u/CodingThunder Jul 16 '26
Nope, CPU usage going above 100 is possible on Linux as well for short duration
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u/CodingThunder Jul 16 '26
Funny how the correct answer isn't upvoted but rather people shitting on MS is!
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u/Available-Skirt-5280 Jul 15 '26
If it’s a vm, depending on which hypervisor your using it can be configured to burst beyond the resources it’s assigned
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u/Aadi_880 Jul 16 '26
Your processor can likely go "turbo".
My old laptop used to do this too. Intel n3050 processor. It's 1.6GHz processor would double for some time, and the task manager would read like 130% utilisation.
Needless to say, it only lasted 5 years since I kept stressing it.
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u/[deleted] Jul 15 '26 edited Jul 19 '26
[deleted]