Incredibly strange CPU usage. Please, please help me.

[Princess]

While I understand this could be more of a software issue, I'm losing my hair stressing out over it. 

 

I was away from my PC for about ten minutes, then I came back. It was super laggy and stuttery, definitely 100% CPU usage, which Task Manager confirmed. I checked Task Manager to see System Interrupts using 100% of my CPU, then around 2 seconds later, it stopped and Antimalware Service Executable alongside Desktop Window Manager were instead doing the same for a few seconds, each at around 20-30%. It completely calmed down, and then Windows Update or whatever ran for a second at a pretty high CPU usage, and after that, nothing.

 

Running a Quick Scan with Windows Defender produces the exact same results. Or, rather, it did, and now it doesn't anymore. The issue is, checking Defender's history, it says the last scan was approximately an hour before this happened. Not only that, but this has happened twice in the span of thirty minutes without Defender saying it performed any scans. 

 

Another concern is that one of the programs that was running and taking up CPU resources was Office, which I had never booted up in my life. 

Here's a screenshot of what happened: 

Can anyone please explain to me what's happening, and if this could be malware? 

 

 

[Princess]

To give more details on the situation, sometimes running Defender Quick Scan does the exact same thing, sometimes it doesn't. If I run it a few times, it does. It always scans around 18420 files, but randomly will slow down sometimes and chug at a snail's pace. Furthermore, the CPU will be at 100% for about a minute after the scan says it's complete.

[Princess]

Update #2, the scans that didn't fail would scan 18420 files, and the latest one that ended up lagging scanned 18560 files, and still didn't seem to complete the full progress bar. 

[LIGISTX]

11 minutes ago, Princess said:

While I understand this could be more of a software issue, I'm losing my hair stressing out over it. 

 

I was away from my PC for about ten minutes, then I came back. It was super laggy and stuttery, definitely 100% CPU usage, which Task Manager confirmed. I checked Task Manager to see System Interrupts using 100% of my CPU, then around 2 seconds later, it stopped and Antimalware Service Executable alongside Desktop Window Manager were instead doing the same for a few seconds, each at around 20-30%. It completely calmed down, and then Windows Update or whatever ran for a second at a pretty high CPU usage, and after that, nothing.

 

Running a Quick Scan with Windows Defender produces the exact same results. Or, rather, it did, and now it doesn't anymore. The issue is, checking Defender's history, it says the last scan was approximately an hour before this happened. Not only that, but this has happened twice in the span of thirty minutes without Defender saying it performed any scans. 

 

Another concern is that one of the programs that was running and taking up CPU resources was Office, which I had never booted up in my life. 

Here's a screenshot of what happened: 

Can anyone please explain to me what's happening, and if this could be malware? 

 

 

Somtimes windows is doing cleanup things in the background, and I have seen the antimalware service be strange like that as well. Just... seems like a windows "feature" to me unfortunately. 

[Princess]

Update #3, after a restart it scanned 43,000 files rather than 18,500 on the first scan, then stopped on a file, and stopped afterwards. Upon attempting another scan, it went down to 18,200. 

[Schofield]

Have you had any luck resolving this?  I am having almost the exact same issue.  System interrupts at 100% CPU usage for a minute or so and then disappears leaving several other programs using unreasonably large amounts of CPU.  Seems to me the system interrupts indicates a problem with hardware or hardware drivers.  Since System Interrupts isn't actually a real program (only a placeholder for the resources being used by the interrupts) I think some hardware issue is causing a high CPU usage and throwing task manager percentages all out of whack (just a theory on why odd programs seem to use high percentages).  Anyway... would really like to figure this out 5 to 10 minutes blips of unusable computer several times a day is quite disruptive to productivity.

 

Tried software updates, used Lenovo Vantage to update all drivers and firmware… not sure what else to try.

 

Basic Specs

Lenovo P73 (thunderbolt dock)

CPU i7-9750H

16 GB DDR4 2666MHz

512 GB PCIe SSD

NVIDIA® Quadro® T2000 4GB

[boola]

I have a similar situation - though not as bad. I'll get some system interrupts at 100% CPU once in a while. 

 

I  have a Lenovo X1 Carbon

CPU i7

16 GM ram

1 TB ssd 

I also have a Lenovo thunderbolt dock with a NVIDIA GTX 1050 inside (Lenovo Graphics Dock).

 

It only happens when I'm docked, so I assume it has to do with my Thunderbolt dock.

[shahed154]

you should uninstall the antimalware service and office and see if that helps, could i get more specs?

also try using cpuid HWmonitor

[Lloyd Void jr.]

On 4/21/2020 at 3:32 PM, Schofield said:

Have you had any luck resolving this?  I am having almost the exact same issue.  System interrupts at 100% CPU usage for a minute or so and then disappears leaving several other programs using unreasonably large amounts of CPU.

Sorry if necro-posting if frowned upon here, but this was the closest description of the the issue I could find when Googling. Setting Intel(R) Graphics Settings > Intel(R) Graphics Power Plan > Plugged in to "Maximum Performance" under Power Options > Advanced settings solved my issue with Windows 10 going haywire with interrupts when my ThinkPad X1 Carbon 5th generation was left unattended while docked with Thunderbolt.