GDM3 vs LightDM Which One Is Better?

When it comes to displaying managers, we have several options to choose from, in the Linux world. They are –

GDM (Gnome Display Manager, in distributions with GNOME DE installed)
SDDM (Simple Desktop Display Manager; in KDE based distributions)
LXDM (LXDE Display Manager, installed on systems with LXDE)
LightDM (Cross Desktop, works with any Desktop Environment).

In this article, we are going to take a look at the differences between Gnome Display Manager (GDM) and LightDM, comparing their features, customization capabilities, and resource usage to help you pick the right one for you.

GDM3 vs LightDM – A Quick Comparison

Well, ideally, you really shouldn’t use any other Display Manager than the one which is shipped with your desktop environment as default. GDM has many dependencies which are used by other components of the GNOME desktop environment, and the same is also true for LightDM.

So unless you are using a window manager like i3WM, i3-gaps, or Sway, or you are changing the Desktop Environments on your system, you shouldn’t hop between Display Managers. But here’s a small comparison of both Window Managers anyway :

Property	GDM	LightDM
System Resource	Heavy usage	Light Usage
Customizability	Little to None	Moderate to High
Ideal DE to use	GNOME	Any DE

Comparison between GDM and LightDM

Introduction to GDM (Gnome Display Manager)

This is the default Display Manager in GNOME, and if GNOME is pre-installed on your distribution, then you’re also probably using this without your knowledge. It is on the heavier side of the display managers, but you’re probably fine with it as you are using GNOME, which is heavy on system resources.

If you are considering using GNOME on old hardware, then I don’t think this display manager will be the right choice for you. It comes pre-installed in many distributions such as Ubuntu, Garuda Linux, Manjaro, Pop_OS! (this will likely change in the future as devs are migrating towards a Rust-based COSMIC Desktop Environment). Some notable features of this Display Manager are:

Efficient and fast User Switching Support
Have accessibility options for specially-abled people.
Compatible with an X server (Xorg) and Wayland
Allows users to customize settings without touching the Terminal

How to Install GDM3

The Installation is really easy, we just have to install it using our package manager on the Terminal :

For Ubuntu and Ubuntu-based distributions :

sudo apt update && sudo apt install gdm3

For Arch Linux and Arch-based distributions :

sudo pacmans -S gdm3

For Fedora Workstation :

sudo dnf install gdm3

Now, we have to enable the GDM service so that it starts on our system startup :

sudo systemctl enable gdm.service

Introduction to LightDM

This Display Manager is designed to be simple, fast, secure, and flexible. And it even supports multiple desktop environments. The developers have kept the source code really simple. Notable Features of LightDM are :

Lightweight and Fast
Highly configurable
Low Memory usage and therefore faster performance
It has low code complexity

How to Install LightDM

To install LightDM on your operating system, use these commands, depending upon your Operating System :

For Ubuntu-based distributions :

sudo apt install lightdm

For Arch Linux and Arch-based distributions :

sudo pacman -S lightdm-gtk-greeter

And for Fedora Workstation, type :

sudo dnf install lightdm

To enable LightDM to run on system startup, enable this service :

sudo systemctl enable lightdm.service -f

Summary

If you’re using the GNOME desktop environment, then it is highly recommended to use GDM due to its compatibility and feature set, and to avoid any dependency-related issues. For any other Desktop Environment, you can choose to use LightDM without any issues as LightDM offers a lightweight, configurable alternative for users who want a simpler, faster display manager that works smoothly with multiple desktop environments. LightDM also has some issue with the NVIDIA drivers and sometimes auto-login doesn’t work on it. But it’s safe to use if you don’t use those features as auto-login poses a security issue and therefore is not recommended.