SteamOS 3.8 is finally here with Steam Machine support and better handheld support

General

• SteamOS now uses a newer Arch system base.
• Valve added initial support for upcoming Steam Machine hardware.
• A connected Steam Controller can now wake the device from sleep.
• Future OS updates should download and install much faster on high-speed connections.
• Game Mode screen casting, including OBS and Discord use cases, has better support.
• Dropdown menus that did not appear in some games have been fixed.
• Valve fixed overly sensitive trackpads on some early Steam Deck LCD units.
• Games that try to open PDF files in external viewers should behave better.
• Remote Play should no longer freeze video output in the affected case.
• Game Recording should no longer crash the session with certain maximum video height settings.
• Valve fixed incorrect game window placement in some titles, including SpongeBob SquarePants: Titans of the Tide.
• Closing some games, including STAR WARS Jedi: Survivor and Starfield, should no longer crash the session.
• Some USB racing wheels and unusual USB devices now have better mode switching support.
• This includes USB devices that initially appear as installer storage and need the OS to switch them into normal device mode.
• Steam Deck controller firmware updates now show progress on the splash screen.
• A firmware update issue that could leave the left controller unavailable for the current session on certain Steam Deck revisions has been fixed.
• Valve included more stability and security updates.

Display and performance

• The graphics driver has been updated with performance and stability fixes.
• Devices with native HDMI output now have preliminary HDMI VRR support.
• "Allow Tearing" should now work correctly in configurations where it previously did not.
• VRR frame pacing has been improved.
• The performance overlay should now show the FSR badge when FSR is active.
• Per-app performance settings should apply more reliably when launching a game.
• Valve added missing graphics features needed by games such as Crimson Desert.
• A blank-screen issue on some TCL TVs with the Steam Deck Dock and VRR has been fixed, with a Dock firmware update required.

Bluetooth and WiFi

• Valve fixed a case where WiFi performance could stay degraded until sleep or manual reconnect.
• Bluetooth Wake is enabled again for Steam Deck LCD.
• The earlier false wake problems from previous Bluetooth Wake attempts should be fixed.

Audio

• SteamOS can now detect HDMI channel count and expose surround options when available.
• A new setting allows Bluetooth headset microphones, with lower Bluetooth playback quality while capture is active.
• If the internal audio device was set to Off in Desktop Mode, it should come back after reboot.
• HDMI audio devices now have a longer suspend timeout so initial audio is less likely to cut off after a few idle seconds.
• Switching input devices with a wired headset connected has been fixed.
• Audio underruns after sleep and resume have been fixed.
• Steam Deck OLED should no longer occasionally lose speaker output after reboot until a second reboot.
• FPS limits should now apply correctly when downscaling games from a higher resolution.

Accessibility

• Valve added a mono audio output option.

Desktop Mode

• KDE Plasma has moved from 6.2.5 to 6.4.3, with Wayland now used by default.
• Desktop Mode should avoid several cases where it performed worse than Game Mode.
• Rotated display support has been improved.
• TV scale factor defaults should be better.
• External HDR displays are now supported.
• VRR displays are now supported.
• Per-display scale factors are now supported.
• Valve points to KDE's Plasma 6.3 and Plasma 6.4 release announcements for more detail.
• Desktop Mode now follows the keyboard layout and language chosen in Game Mode.
• Proton game window behavior has been improved.
• Desktop Mode should now remember previously open apps correctly when using Return to Gaming Mode to log out.
• Experimental nested desktop mode received fixes.
• Night Color settings from Desktop Mode should no longer stay active after returning to Game Mode.

System firmware

• Steam Deck LCD now includes BIOS v133.
• The LCD BIOS includes security updates.
• Steam Deck LCD now has a Memory Power Down setup option.
• Steam Deck LCD gets preliminary hibernation support.
• Steam Deck OLED now includes BIOS v114.
• The OLED BIOS includes security updates.
• On Steam Deck OLED, the charging LED now changes color when the configured charge limit is reached, not only at 100 percent.

Non-Deck devices

• SteamOS has better compatibility with recent Intel and AMD platforms.
• Discrete GPU systems have much better video memory management.
• Valve fixed a SteamOS chainloader issue that could stop some desktop systems with newer UEFI firmware from booting.
• Short and long power button presses now work across more devices.
• Controller support has improved for OneXPlayer F1 series, GPD Win 5, GPD Win Mini, Anbernic Win600, OrangePi NEO, and Lenovo Legion Go.
• OneXPlayer X1 series and Lenovo Legion Go 2 now have controller support.
• Lenovo Legion Go 2 now has system and controller firmware update support.
• Legion Go, Legion Go S, and Legion Go 2 now have early charge limiting support in Desktop Mode.
• Lenovo Legion Go 2 now has controller RGB LED color settings.
• ASUS ROG Xbox Ally devices now have controller, TDP control, and speaker audio support.
• Handheld controller input latency has been reduced from the previous 5 to 8 ms range to roughly 100 to 500 us.
• Steam's night mode, color vibrance, and color temperature sliders now work on AMD Z2E and newer APUs.
• AMD Z2E and newer APU devices get seamless boot fixes.
• SteamOS can automatically handle internally rotated displays on some third-party handhelds.
• Handhelds with BMI260 IMUs should have better motion control support.
• SD card reliability has been improved on some third-party handhelds, including ASUS ROG Xbox Ally, Legion Go 1, Legion Go S, Legion Go 2, and MSI Claw.
• Washed-out colors on Zotac and OneXPlayer OLED handhelds have been fixed.
• Valve fixed some GPU hangs on Phoenix APU devices, including issues seen in Tales of Arise and Octopath Traveler II.
• ASUS ROG Ally fingerprint reader power draw while shut down has been fixed.
• Legion Go trackpad functionality after sleep and resume has been fixed.
• False wake-ups with Logitech Bolt receivers have been fixed.
• MSI Claw A1M, 7 AI+ A2VM, 8 AI+ A2VM, and A8 BZ2EM now have controller support.
• OneXPlayer APEX and X1 series now have controller support.
• Devices using AccelGyro3D, including Legion Go 1 and Claw A1M, should have better gyro response.
• Valve fixed a system crash on international ASUS ROG Xbox Ally models.
• Bluetooth should now work on affected Intel handhelds.
• Valve added initial firmware for upcoming Intel handhelds.

Developer changes

• Desktop Mode now uses Wayland by default.
• X11 can still be selected through Steam developer settings or steamosctl.
• The Linux kernel is now 6.16.
• Steam now uses steamos-manager to query desktop sessions and switch between sessions.
• Developer settings now support setting the desktop password.
• SteamOS now has initial virtual machine guest support through virtio drivers.
• Third-party devices can trigger the SteamOS boot menu through an EFI variable.
• atomupd-manager now has a custom-update verb for easier specific-build testing.
• System reports now include more audio debug information.
• SteamOS now has initial LAVD CPU scheduler support through steamosctl set-cpu-scheduler lavd.