Recently, I needed to configure fractional scaling for two displays: my laptop's 4K screen and my external 2K monitor. I quickly discovered that Ubuntu 24.04 doesn't support different fractional scaling settings across multiple displays. Reference.

Solution:

• Step 1: Upgrade to Ubuntu 24.10. This version replaces X11 with Wayland for NVIDIA graphics cards. Using Wayland as the default display server resolves the fractional scaling issue. After upgrading, remove all existing NVIDIA drivers and install version 570:

sudo apt purge nvidia-\*
sudo apt install nvidia-driver-570
sudo apt install nvidia-cuda-toolkit
sudo apt install nvidia-cudnn

Restart your PC.

• Step 2: After configuring scaling, you may notice Chrome appears blurry. To fix this:
  • Navigate to chrome://flags in your Chrome browser
  • Search for Preferred Ozone platform
  • Select Wayland option
  • Restart Chrome

• Step 3 (optional): Fix bug nvidia-smi eating all your RAM, then being killed (2025/05/09):

  • This is a very weird bug of nvidia-smi that ate all my RAM > https://forums.developer.nvidia.com/t/nvidia-smi-uses-all-of-ram-and-swap/295639.
  • Fix this: You can use sudo chmod o-w /var/run/nvidia-persistenced/socket to fix it temporarily.
  • For persistent workaround:

  sudo mv /usr/bin/nvidia-smi /usr/bin/nvidia-smi-bug
  sudo nano /usr/bin/nvidia-smi
  

  then paste:

  #!/bin/bash
  
  sudo chmod o-w /var/run/nvidia-persistenced/socket
  nvidia-smi-bug
  

  Ctrl+x to save, then

  sudo chmod +x /usr/bin/nvidia-smi
  

  Now you can run nvidia-smi as usual, but it requires root permission.

Done! Enjoy your fractional scaling! :D