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Hi,
I noticed that displaying memory usage has two types, values and percents, in processes tab of task manager in Windows. The data of values type is from private working set memory. I'd like to know where the data of percents is from and how to calculate it in task manager.
Please give me some details about the percents. What are the numerator and the denominator to calculate memory used percents?
Thank you.
I got correct answer of calculating memory usage percentage.
percentage of a process = (current private working set of a process/ sum of all processes’ private working set) * current total memory usage percentage.
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The percentage depends on the size of the memory, for example when you have more memory the percentage is lower. It shows how many percent of memory is being used. It is based on the size of memory has been occupied for each process.
I would like to know the exact calculation formula.
Task Manager calls NtQueryInformationProcess with ProcessVmCounters and returns PrivateWorkingSetSize from VM_COUNTERS_EX2
From my tests, to get the percentage, it seems to compare with the sum of PrivateWorkingSetSize for all processes.
I tested this method, however, it does not work on my machine. The calculated value is smaller than percent from task manager.
How did you calculate the value ?
Did you list all processes with NtQuerySystemInformation and SystemExtendedHandleInformation ?
I used NtQuerySystemInformation and SystemFullProcessInformation to list all processes. And then I use WorkingSetPrivateSize and the sum of WorkingSetPrivateSize of all processes to calculate percents.
Hi there,
The percentage is nothing but the total memory used vs the installed memory. For example if you have 32gb installed memory and you are using 16gb then it is 50% usage.
You can also use other tools like Process Monitor which is an advanced monitoring tool for Windows that shows real-time file system, Registry and process/thread activity.
Process Monitor v3.89
https://learn.microsoft.com/en-us/sysinternals/downloads/procmon
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No.
It is PrivateWorkingSetSize not Working Set size...
