High CPU usage, even without a real reason
I see Chromium browser which is responsible for high CPU as per screenshot provided of htop command.
That simply means there is something wrong with your Chromium browser.
To check for problems, hit Shift+ESC to while using Chromium to bring up the Chromium task manager, and check out which sub-process is using highest CPU, it may be some extension or a Browser Tab.
Also make sure to disable "Continue running background apps when Google Chrome is closed" under Chromium Settings>Advanced. This option makes Chromium running even after all Tabs are closed which may cause high resource usage on some systems.
I had the same thing and tried several things; which I'd found while debugging what the cause was:
- Disabled the
Accelerated 2D canvas; can be found here chrome://flags/ - Disabled most of the GPU processes under that same page.
- Checked the Task Manager of chrome, which only indicated that the
browseritself was taking that high CPU(i.e. 151!!)
Tried each one and restarted chrome after each, but in vain! However, Restore settings to their original defaults did work. But unfortunately, I don't know what caused the high CPU usage, but yeah that did the trick!
chrome://settings/ => Advanced Settings => Restore settings...etc
Hopefully that helps!
I think your main issue appears to be that you are running in software rendering mode. This is utilizing your CPU instead of GPU for rendering. Go to Software & Updates on the Additional Drivers tab to make sure you are running the correct video drivers.
I also noticed in your original screenshot of htop that you were 2GB into your swap space. As you start to run out of swap space, kswapd will chew up a lot of CPU and IO. The only solutions here is to have less stuff running or to add more memory to the computer.
EDIT: The op has since changed the screenshot to one where Chrome is using the majority of the CPU. The original screenshot was not a Chrome issue.
For anyone encountering the high CPU usage issue recently (December 2020), mine was resolved by making sure I had more than 2GB of free disk space on the root partition (Ubuntu 16.04).
This solution was suggested by Martin S. 1301 on this support thread: https://support.google.com/chrome/thread/49032533?hl=en&msgid=51383298