gamescope

I think your information is quite outdated. The HWC overlay planes are heavily used, you can see this trivially just doing a 'dumpsys SurfaceFlinger' or grabbing a systrace/perfetto trace. When it falls back to GPU composition it's very obvious as there's a significant hit to latency and more GPU contention. The overlay capabilities of the modern Snapdragons are also quite absurd. They support like upwards of a dozen overlays now and even have FP16 extended sRGB support. Some HWCs (like the one in the steam deck) even have per plane 3D LUTs for HDR tone mapping (ex https://github.com/ValveSoftware/gamescope/blob/master/src/d... ) The composition is bandwidth heavy of course, but for static scenes there's a cache after the HWC in the form of panel self refresh.

The readme pretty much explains it: https://github.com/ValveSoftware/gamescope

One of the unfortunate things about Wayland is every compositor will have its own quality of implementation affecting things like latency. With XOrg, especially in the pre-compositing days, you could choose whatever WM you want and it wouldn't have any impact on the rendering performance of X clients. Once the Composite extension was added and everyone started running composited X desktops, that started to change, and the increased latency already started appearing - in an arguably worse architecture than Wayland because there were often three processes involved with lots of IPC/context switches per draw: X-Client->X-Server->X-Compositor->X-Server->CRTC. At least in Wayland it's more like Wayland-Client->Wayland-Compositor->CRTC. If you're unhappy with the rendering latency of your Wayland sessions, it may be worth trying alternative co

I use Wayland KDE but have shortcuts for Steam to launch within Gamescope []. # normal steam with experimental HDR enabled, native resolution for my laptop and 165hz refresh rate. alias steam 'steam-run gamescope -f --hdr-enabled -e -W 2560 -H 1440 -r 165 -- steam' # full screen gamepad ui alias steam_gamepadui 'steam-run gamescope -f --hdr-enabled -e -W 2560 -H 1440 -r 165 -- steam -gamepadui' Computer is Asus G513qy, a a full AMD laptop with discrete graphics. Janky thermal design, no thunderbolt... so more like a stationary desktop. Wouldn't buy something like this again but for now it does the job and runs great with any modern distro. [] https://github.com/ValveSoftware/gamescope

steam deck is indeed wayland with their own compositor called gamescope[1] for low-latency gaming (they target the fewest buffer copies as possible). Another nice side-effect it has is hdr support on AMD GPUs. 1: https://github.com/ValveSoftware/gamescope

I have an Intel GPU (HD Graphics 520) and gamescope doesn't work for me under arch Linux :( https://github.com/ValveSoftware/gamescope/issues/356

For those that don't know (like me, three minutes ago) gamescope [1] is a Wayland compositor custom-written for games (and, I believe, what the Steam Deck uses). it's open source, and under the "BSD 2-clause" license. [1]: https://github.com/Plagman/gamescope