I was getting pretty bad performance using Ubuntu 20.04 with a Dell XPS 9343. I upgraded to the yet-to-be-released Ubuntu 20.10 hoping it will help.
It did - performance is much better now.

This short post explains how to upgrade Ubuntu 20.04 focal to Ubuntu 20.10 groovy.

Steps

  1. Backup your important data to the cloud or external drive. Upgrading is always a risky process, better be safe than sorry.
  2. Update package information
    sudo apt update
  3. Make sure all packages are up-to-date
    sudo apt upgrade
  4. Replace apt repositories list from focal to groovy
    sudo sed -i 's/focal/groovy/g' /etc/apt/sources.list
  5. Update packages information from the new groovy repos
    sudo apt update
  6. Upgrade to Ubuntu 20.10
    sudo apt dist-upgrade
  7. Validate Ubuntu version
# lsb_release -ca
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu Groovy Gorilla (development branch)
Release:	20.10
Codename:	groovy

I'm running Ubuntu 20.10 over a week and so far so good.
Let me know how it works out for you!

Troubleshooting

  • Broadcom Wi-Fi driver doesn't work
    I had a minor problem with the Broadcom Wi-Fi driver crashing and not working after the upgrade.
    To solve that:
sudo apt-get remove --purge bcmwl-kernel-source
sudo apt-get install broadcom-sta-source
sudo apt-get install broadcom-sta-dkms
sudo apt-get install broadcom-sta-common
# reboot