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Windows 7: Completely random CPU usage

03 Jun 2014   #1

Windows 7 Professional x64
Completely random CPU usage

Hello, I registered to these forums as I need help with the problem I encountered with my PC.

Some time after startup ( Not right away ) my CPU usage goes to 100%. I open task manager and kill the process which takes most of the CPU and then another process gets the high usage and so on untill some system process which I am afraid to kill or some app that I need gets it.

Problem started happening a while ago, I thought it's just a problem with my OS which collected garbage over the time as I didn't really keep it clean. Few days ago I reinstalled my OS and this thing is still happening and I really have no clue on what it is or how to fix it.

I provided a screenshot of resource monitor below, it shows that resmon itself uses 24% of the CPU which I find quite weird.

Note: System is updated with the latest updates from windows update. I also have AVAST Premier and I run a boot scan 2 days ago and it didn't detect any virus.

Attached Thumbnails
Completely random CPU usage-stuff.png  
My System SpecsSystem Spec
03 Jun 2014   #2

Win7 Ultimate X64

I would start with safe mode and/or a clean boot to see if the problem persists
Troubleshoot Application Conflicts by Performing a Clean Startup
clean boot will remove all third party drivers where as safe mode will only run basic drivers, just enough to make the system boot and operate
My System SpecsSystem Spec
05 Jun 2014   #3

Windows 7 Professional x64

I took a look into my PC's temperatures and it said CPU is at 80+ degrees. I changed the pasta thingy, cleaned it from dust and added a new cooler to my GPU ( GPU wasn't really over-heating, but summer is coming and stuff will become even hotter ) and it seems to solve the problem.

Now, I am having a hard time understanding how can temperature cause things that I said above.
My System SpecsSystem Spec

05 Jun 2014   #4


The probable reason for those results is the way resource monitor calculates CPU usage. When you were running hot you were probably throttling and your CPU run at reduced maximum frequency, let's say for example 1GHz. So any time there was higher load requiring your CPU running at 1GHz monitor would show 100% utilization at that particular moment, since it knew your CPU can't run any faster. After cleaning, your CPU runs cool and can go to lets say it's real max 2GHz, so now with the same load as before requiring CPU again running at 1GHz to perform all tasks, the monitor will show 50% cpu utilization at that particular snapshot, since it still has headroom to go 2X as fast. Hope this is clear.
My System SpecsSystem Spec
07 Jun 2014   #5

Windows 7 Professional x64

Ok, thank you very much for that explanation.
My System SpecsSystem Spec

 Completely random CPU usage

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