I'm using Xubuntu 20.04 on a desktop PC with a Ryzen 2400g CPU and 2x8gb RAM but having just a few tabs open in chromium uses all of my CPU and more.
The fan on my PC goes in to overdrive and checking top shows the following:
I use both FF and Chromium (both installed from snap) and with FF there are no such problems.
Anyone have any ideas why this is happening/how I can stop it?
Try using task manager (from More tools menu or by Shift+Esc) to see which tab is causing high CPU usage.
After further testing, the problem was something to do with Chromium itself and not any web resources. The problem happened on many different wep pages and there was no apprent reason. CPU usage rose and stayed at 200% continuously.
The only solution was to uninstall Chromium and to install Ungoogled Chromium.
https://ungoogled-software.github.io/ungoogled-chromium-binaries/
echo 'deb http://download.opensuse.org/repositories/home:/ungoogled_chromium/Ubuntu_Focal/ /' | sudo tee /etc/apt/sources.list.d/home:ungoogled_chromium.list
curl -fsSL https://download.opensuse.org/repositories/home:ungoogled_chromium/Ubuntu_Focal/Release.key | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/home:ungoogled_chromium.gpg > /dev/null
sudo apt update
sudo apt install ungoogled-chromium
The problem is now fixed, Chromium uses little CPU:
Though I'm not going to mark this as the correct answer as it's not exactly a fix, but personally I think it's the best option