Very high CPU usage (processes not adding up)

allam447635 · 05 Feb 2018

This morning, I was playing Minecraft, and I noticed my computer fan suddenly getting higher in pitch. I went into Task Manager and noticed that the CPU usage was always above 70%, but there were no processes using more than 10% (Normally the game uses about 30-40%, but I had to pause to check). I knew something was off because the game was the only process using more than 10% CPU, and there were surely less than 10 processes in the 3-10% range. This persisted even after I closed the game. When I looked at the task manager graph, it looked like there were two graphs, one showing the actual CPU usage, and the other not accounting for the mysterious usage. I also noticed my CPU speed was exceeding 3 GHz even though it says the maximum speed is 2.5 GHz (not sure if that's related but it might be).

I tried putting the computer to sleep and waking it up again but I knew this didn't work because the fan was making a racket the second I woke the computer up. I noticed that this had lowered the mysterious usage, but did not get rid of it. Rebooting my computer fixed it.

TairikuOkami · 06 Feb 2018

You might be infected with coinminer malware. Download Process Hacker, run Minecraft, then close it.
Open Process Hacker, doublick the process, open Threads, sort it by CPU to see, what is taking CPU.

allam447635 · 06 Feb 2018

TairikuOkami said:

You might be infected with coinminer malware. Download Process Hacker, run Minecraft, then close it.
Open Process Hacker, doublick the process, open Threads, sort it by CPU to see, what is taking CPU.

This doesn't happen every time I play, and yesterday was actually the first time I remember this happening. Again, rebooting got rid of the mysterious usage, and every time I checked the Task Manager while playing since then, it hasn't happened, so I don't think it's malware.

allam447635 · 22 Mar 2018

This is happening again right now. I don't know why. I didn't even have anything running when it started. Let me post a screenshot of what the CPU graph looks like:

Very high CPU usage (processes not adding up)-there-two-graphs.png

Rebooting fixed it last time so I don't think it's malware.

MeAndMyComputer · 22 Mar 2018

Based on an experience about 6 months ago in which I helped a friend deal with his computer that essentially had the same problems you are seeing, here are my thoughts:

His CPU usage showed similar graphs like you show including excessive speed. Open your computer case and clean out the fins of the CPU heat sink as well as everything including the fans.
--- He also had inconsistent fan noises.

After that run your Internet Security programs. I know you don't suspect malware to be an issue but neither did my friend. It's worth verifying.
His Internet Security program wasn't catching a lot of items I found by running a 2nd opinion security program: Malwarebytes Premium 14-day free trial.
--- 91 PUP's and 1 Trojan was found: none of those PUP's had any business being on his computer so I had everything removed.
--- After that I had his Internet Security program updated to ensure it was running the way it's supposed to.

The computer still runs as good as new.

Good luck