Often the CPU usage reported in the System load tab is higher than the sum of the usage of the single processes in the the Process Table tab. Looking at the processes CPU usage with 'top' show more realistic values. Related: https://bugs.kde.org/show_bug.cgi?id=288563
Thanks for the report. Could you describe in more detail how to reproduce the behaviour? Do you use the "Stack the beams on top of each other" (see https://bugs.kde.org/show_bug.cgi?id=388581)?
Created attachment 111658 [details] Process table
Created attachment 111659 [details] System load
Steps: - PC in idle - Sort process table by CPU usage - Roughly sum the % of CPU usage of the top processes (the ones with a percentage displayed, many other processes do not show a percentage probably because is elow 1%) [In this moment my sum is about 15% in the worst case) - Look at the CPU usage in the System load tab (configured to stack the beams with range 0-400%, my CPU has 2 cores and 4 threads) [In this moment the usage is above 80%] These two numbers differ significantly. Also considering only 2 out of 4 threads the percentage would be 40% not 15%. BTW: Would be useful to have the total CPU usage displayed somewhere in the process table, but this is another bug report.
Thanks for (In reply to Simone Gaiarin from comment #4) > Steps: > ... Thank you for the details. > BTW: Would be useful to have the total CPU usage displayed somewhere in the > process table, but this is another bug report. Have a look at the status bar of your Process Table screenshot. The second item might be what you are looking for.
Yes you are right. Anote: the CPU sum in the status bar seems more similar to what is displayed in the system load tab than to the effective sum of the cpu load of the individual processes in the processes tab.
(In reply to Simone Gaiarin from comment #6) > Yes you are right. > > Anote: the CPU sum in the status bar seems more similar to what is displayed > in the system load tab than to the effective sum of the cpu load of the > individual processes in the processes tab. Do you think the status bar shows indeed the correct sum or do you assume a bug there, too?
I think the sum in the status bar does not sum exactly the individual processes. I've added another screenshot.
Created attachment 111736 [details] Ststus bar CPU sum does not match sum of processes
issue described in sunmary is valid for ksysguard 5.12.4 on Arch Linux.
I can confirm that for Fedora 28-31, OpenSUSE 15-15.1
ksysguard is no longer maintained, in Plasma 6 there is the Plasma system monitor for this task. If your issue still happens with the Plasma 6 replacement, please re-open and we can move this bug to the new product, thanks!