Pop!_OS Cosmic Steam Deck Mode And The Results Are Wild

Following on from the Linux Mint video where the Gamescope launcher produced some unexpectedly high benchmark results, it's time to put Pop!_OS Cosmic through the same test. Same hardware, same games, same settings — let's see what happens.

website/and link to scripts : https://www.no-signal.uk

Spoiler: the results pretty much prove the theory. Strip away the desktop environment, run Gamescope as a dedicated compositor on top, and the hardware just does what it does. The scores are almost identical across the board. Almost.

HARDWARE
5060 Ti 16GB, Ryzen 9, games running off an external NVMe over Thunderbolt/USB4. Resolution locked at 2560x1440. HDR switched off because the system falsely detects it.

GAMES TESTED
Returnal — Proton GE, DLSS quality at 67% upscaling, everything on Epic. Score: 97 FPS. Exactly the same as Linux Mint. MangoHUD was actually matching the in-game frame rates this time, unlike the Mint session where it was way off. Solid result and right in the sweet spot for this system.

Doom Eternal — Proton GE, DLSS quality, triple buffering on, v-sync off, max texture memory. Score: 85 FPS. Frame graph was flat and smooth, no stuttering. Again, right in line with what Mint produced and what I'd expect from CachyOS and Omarchy too.

Cyberpunk 2077 — Proton GE, ultra ray tracing, DLSS auto, no frame generation, 1440p. Score: 88 FPS. Now this is where it gets really interesting. On Mint, Cyberpunk pulled 95 and 96 across two runs — the highest I've ever seen on this machine. On Cosmic, it's back to the 88 I normally see on Omarchy and CachyOS. So the Mint result is still an outlier and I genuinely cannot explain it. Same settings, same process, checked it twice. I'm going to have to reinstall Mint and retest because something was going on there.

THE BIGGER PICTURE
This is exactly what you'd expect when you think about it logically. The hardware hasn't changed. Gamescope is acting as its own Wayland compositor, sitting directly on top and talking straight to the GPU. The desktop environment is completely out of the equation. So whether you're on Mint, Cosmic, Omarchy, or CachyOS, you should get the same results — and that's exactly what's happening, give or take a frame.

It raises a really good question about the whole debate around which distro is fastest for gaming. If you're running Gamescope, the distro underneath matters far less than people think. CachyOS might have a newer kernel and optimised scheduling, but once you've stripped everything back to just the compositor and the game, the difference vanishes.

The one thing Cosmic does differently is the loading times. Games took noticeably longer to get going compared to the Mint and Omarchy versions. I haven't dug into why yet — could be something in the session switching, could be a package difference, could be something I've missed in the conversion. If anyone in the members area runs into the same thing or has ideas, let me know.

POP COSMIC THOUGHTS
I talk a bit in this one about how close I came to going all-in on Cosmic before Omarchy landed. The tiling window manager was exactly what I was after, and if Omarchy hadn't come along when it did, this channel would probably be wall-to-wall Cosmic content. It's a genuinely good OS and the gaming performance through Gamescope backs that up.

LAPTOP AND MULTI-MONITOR NOTES
This script is tested on a single-screen wired desktop setup. Gamescope is designed for one screen — you can't run Discord on a second monitor alongside it, that's not how this works. On laptops you need to be on the dedicated GPU and bypass the iGPU. There's a separate Intel script available if you're on Arc. Multi-monitor setups will need some manual config in the Gamescope config file.

THE SCRIPT
Available in the members area as always. Download it, try it, and if you hit issues let me know through the members channel. It's much easier for me to help and iterate when I've got a direct dialogue going rather than pushing scripts out publicly and getting swamped with system-specific issues that never get followed up on.

WHAT'S NEXT
CachyOS is up next. I'll run the install and benchmarks and then put together a proper comparison video with all the scores side by side. The Mint Cyberpunk result is still bugging me, so expect a revisit on that too.

I make videos about Linux gaming, Arch-based distros, hardware tinkering, and getting the most out of your setup. If that's your thing, subscribe and stick around.