Vultures rake our claws over COSMIC as Pop OS 24.04 LTS with 'Epoch 1' emerges

Hands On It's been a long time coming but version 1.0 of the first ground-up Rust-based desktop is here… and it is shaping up very well.

Late last week, System76 officially released the long term support version of its in-house Ubuntu remix along with "Epoch 1" of its in-house desktop environment COSMIC, implemented from scratch in Rust. After testing out the beta version in VMs and on an old clunker, we tried it on a more modern testbed, and we are grudgingly impressed.

The COSMIC desktop has been quite a long time coming, but building a whole new desktop is not a trivial exercise. The Register first reported on the project just over four years ago. We looked at the alpha test release in September, and later the beta version. Now, as promised at the Ubuntu Summit last month, version 1.0 of the COSMIC desktop is here, as well as its native distro, the Ubuntu Noble-based Pop!_OS 24.04.

We have been testing it out on the highest-end of our old Thinkpads, a W520. It works and makes this nearly 15-year-old PC feel remarkably fast, but we experienced regular freezes, for instance when opening a bunch of Firefox tabs. Up to a point, that is fair enough: the machine has long-supported Nvidia Quadro 1000 second GPU, which was last supported by NVIDIA's Linux drivers three whole major versions ago. We're rather surprised it worked at all, let alone worked well. So, decided it would be fairer to try it on the newer Reg FOSS desk testbed, a Dell XPS 13 9370.

COSMIC handles two screens with aplomb, which is more than we can say for its screenshot tool – click to enlarge

This is not a trivial exercise. Pop!_OS uses the systemd-boot boot loader instead of GRUB. That keeps the files for the Linux kernel and initramfs inside the PC's EFI System Partition. Dell only configures a paltry 100 MB ESP, and the release version of Pop!_OS refuses to install. Using the very latest Gparted Live 1.70-12, released just a few days before, we shrank the Windows 11 partition, moved its start 900 MB later on the disk, and then tried to enlarge the ESP. It didn't work. Just as we reported way back in 2021, the underlying disk-resizing tool used by GParted can't handle FAT32 volumes this small. It still throws an error and says "we're working on it." Well, the GNU Parted team isn't working on it with any urgency, because it's still broken over four years later.

We worked around this by temporarily copying the EFI files somewhere else, deleting the tiny ESP, making a new one of 1000 MB, copying the Windows and Debian files back into it, and then installing a clean new copy of Pop!_OS. The new distro works fine, but for now, we can no longer boot Windows 11 or Debian. Summary: watch out – Pop!_OS still does not play nicely with dual boot.

It also defaults to some memory-management settings that wouldn't be our first choice. It configures two levels of swap: ZRAM memory compression, then an much lower-priority encrypted swap file on disk – although it seemed happy to use an existing dedicated swap partition, it still encrypted it. The Dell XPS 13 has 16 GB of non-upgradable RAM, which isn't much but isn't desperate, and it does have a fast SSD. So we wanted our favored performance optimizations, with a more conventional, single-level swap setup. We removed ZRAM by removing the config package:

apt purge pop-default-settings-zram

Then we disabled encryption and rebooted. Next, we added the existing swap partition to /etc/fstab, rebooted, and checked it was working. Then, we enabled swap compression: Zswap instead of ZRAM. Rather than swapping to a compressed RAMdisk, and if that fills, spilling to an encrypted swap file or partition, this way the kernel compresses data as it's written to a swap drive instead. It keeps more RAM free, reduces the amount of data written to swap, and also reduces SSD wear. To do this with systemd-boot, we edited /boot/efi/loader/entries/Pop_OS-current.conf and added zswap.enabled=1 to the end of the kernel line. Another reboot and all was well, and very fast indeed.

On this less-compromised hardware, Pop!_OS never missed a beat. We added an external USB-C screen, and a USB-C dock for an external keyboard and mouse. It handled these fine, including sleep and resume, docking and undocking, and moving apps between different desktops. We tried to load it up with a large Flatpak Electron app, the Ferdium multi-protocol chat client, and an Electron Appimage (the Panwriter Markdown editor, and both Firefox and Chrome, all at the same time. It never perceptibly slowed, and the combination of automatic window tiling and dynamic virtual desktops kept things usable even on a small screen.

COSMIC is still version 1.0 and it does feel like it in places. It doesn't always pick up changed settings immediately. Some parts are a bit clunky. The main panel easily gets overcrowded, and it doesn't work very well in vertical orientation – but it works at all, and at least it's an option, unlike in Windows 11. You can have a panel and a dock, or just one or the other, or a taskbar, whatever you want – even status icons – without messing around with extensions, unlike in GNOME.

Even so, what's here is good and it's certainly usable. We would go so far as to say that in terms of Wayland desktop environments, at the end of 2025, this is the state of the art. Windows snap open; press Windows+T for a terminal, and immediately you're looking at a bash prompt. We downloaded the Panwriter appimage, made a new folder, moved it into it, all by just guessing the keystrokes, and it worked perfectly. Alt+Enter for the file properties did not work, but one right-click later, we added execute permission, and it just worked – first time. Firefox and Chrome picked up the settings from the previous install of CachyOS which used the same home directory; Firefox even reopened our last browsing session. A full installation only took about 8 GB of disk space, although it did use a lot of RAM – htop reports 1.6 GB in use at idle.

COSMIC isn't pretty, but it's not hard on the eyes either. It's a little clunky in places. The fake menu bar in some COSMIC apps doesn't work very well, but it's better than a hamburger menu. Not many standard CUA-style keyboard shortcuts work, but that's also true of both GNOME and KDE, and they've both had over a quarter of a century to get this right.

There are already some add-on applets available in the COSMIC app store, such as both minimal and full-featured Start-menu equivalents. It has also made its way into multiple distros already, and by early 2026 you should see COSMIC Epoch 1 in Arch and other rolling-release distros.

This is the first desktop environment we've seen that delivers any of the promised benefits of Wayland. It's very fast, can handle changing resolutions, orientations, scaling factors and so on on the fly without any issue. Both GNOME and the various tiling Wayland compositors face serious new competition.

Several of the Reg FOSS desk's techier friends were already running Pop!_OS, but the new desktop makes it even more appealing. It also shows that the underlying Ubuntu 24.04 OS is no slouch. We think this is a winning combination which will win win Pop!_OS a lot of new admirers – and help burnish System76's reputation, too. ®

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Vultures rake our claws over COSMIC as Pop OS 24.04 LTS with 'Epoch 1' emerges