SteamOS 3.8 Preview Brings Initial Support for Steam Machine

Valve has just introduced a preview of its SteamOS 3.8 operating system, designed for the Steam Deck and other upcoming hardware. This version marks a significant step toward enabling the future Steam Machine, as the SteamOS 3.8 preview build includes initial support for it. This update comes with a host of improvements, such as better support for third-party handhelds, reduced input latency of handheld controllers, optimized graphics drivers with performance and stability fixes, a new KDE desktop environment build, and support for a wider range of Intel and AMD SoCs. For the upcoming Steam Machine, we anticipate optimizations for a semi-custom six-core AMD “Zen 4” processor with 28 compute units of RDNA 3 graphics. Valve claims the PC can achieve 4K gaming at 60 FPS with ray tracing and FSR support. It features 16 GB of DDR5 system memory and 8 GB of GDDR6 VRAM, powering a semi-custom GPU that may be closer to AMD’s RDNA 3.5 than pure RDNA 3.

A complete changelog of added features follows.

General

• Initial support for upcoming Steam Machine hardware
• Updated Arch system base
• Updated graphics driver with performance and stability fixes
• Fix a case where per-app performance settings would intermittently fail to apply when launching a game
• Improved support for the screencasts in Game Mode (e.g. OBS/Discord)
• Fixed dropdown menus not appearing in some games
• Improved VRR frame pacing
• Fixed FSR badge remaining off in the performance overlay, even if it was actually active
• Improved support for games that attempt to open PDF files in external viewers
• Fixed an issue affecting certain titles (such as “SpongeBob SquarePants: Titans of the Tide”) where the game window could have an incorrect position
• Fixed closing certain titles (such as “STAR WARS Jedi: Survivor “) and Starfield resulting in a session crash
• Improved support for certain USB racing wheels and USB devices that boot in a non-standard mode
• Frequently these are devices that appear as USB storage devices with a driver installer, and must be switched to their normal mode by the OS
• Steam Deck controller firmware updates now display update progress on the splash screen
• Fixes issue on specific Steam Deck revisions where firmware updates could render the left controller inoperative for that session
• Numerous stability and security updates

Bluetooth

• Re-re-enable Bluetooth Wake for Steam Deck LCD
• Fix for more spurious wake issues that were present in earlier attempts

Audio

• Detect HDMI channel count and expose surround configuration if available
• Add a setting to allow using Bluetooth headset mics (Bluetooth playback quality will be worse while capture is active)
• Restore internal audio device on reboot if set to “Off” in desktop mode
• Increase suspend timeout for HDMI devices so initial audio isn’t cut off after a few seconds of inactivity
• Fixed a bug with switching input devices when a wired headset is plugged in
• Fixed an issue where audio underruns could be experienced after sleep/resume

Accessibility

• Added an option to force mono audio output

Desktop Mode

• KDE Plasma updated to version 6.4.3 from 6.2.5, and now uses wayland by default
• Fixes several cases of reduced performance in Desktop Mode compared to Game Mode
• Improved support for rotated displays
• Better scale factor out of the box on TVs
• Adds support for external HDR displays
• Adds support for VRR displays
• Adds support per-display scale factor
• For more information, see Plasma release announcements
• Keyboard layout and language are now obeying Game Mode settings
• Improved windowing behavior for games running in Proton

System Firmware

• Includes Steam Deck LCD BIOS v133

Security updates

• Added “Memory Power Down” setup option
• Preliminary support for hibernation
• Includes Steam Deck OLED BIOS v114
• Security updates
• Charging LED now changes color when charge limit is reached, rather than only at 100%

Non-Deck

• Improved compatibility with recent Intel and AMD platforms
• Greatly improved video memory management with discrete GPU platforms
• Fixed a compatibility issue with the SteamOS chainloader that could cause a boot failure on some desktop systems with recent UEFI firmware
• Power button short and long presses now supported across a wide variety of devices
• Improved controller support for OneXPlayer F1 series, GPD Win 5, GPD Win Mini, Anbernic Win600, OrangePi NEO, and Lenovo Legion Go
• Added controller support for OneXPlayer X1 series and Lenovo Legion Go 2
• Added system and controller firmware update support for the Lenovo Legion Go 2
• Added preliminary charge limiting support for Legion Go, Legion Go S, and Legion Go 2 – currently only accessible in Desktop Mode
• Added controller RGB LED color settings for the Lenovo Legion Go 2
• Added controller, TDP control, and speaker audio support for the ASUS ROG Xbox Ally series
• Reduced handheld controller input latency from 5-8 ms to 100-500 us
• Night mode, color vibrance, and color temperature sliders in Steam now work on Z2E and later AMD APUs
• Seamless boot fixes for Z2E and later AMD APUs
• Automatically handle internally rotated display for some third-party handhelds
• Improved motion control support for handhelds with BMI260 IMUs
• SD card reliability improvements for some third-party handhelds, including ASUS ROG Xbox Ally, Legion Go 1, Legion Go S, Legion Go 2, and MSI Claw
• Fixed washed out colors for Zotac and OneXPlayer handhelds with OLED
• Fixed some GPU hangs on Phoenix APU devices (Tales of Arise, Octopath Traveler II)
• Fixed ASUS ROG Ally power consumption from fingerprint reader while shut down

Developer

• Desktop Mode now uses Wayland by default
• X11 support may still be selected via Steam developer settings, or via ‘steamosctl’
• Updated Linux kernel to 6.16
• Steam now uses steamos-manager to query available desktop sessions and trigger desktop session switching
• Added support for setting the desktop password in developer settings
• Initial support for running as a Virtual Machine guest (virtio guest drivers)
• Added support for third-party devices to trigger the SteamOS boot menu via EFI variable
• Added ‘custom-update’ verb to ‘atomupd-manager’ for easier testing of specific builds
• System reports now include more audio debug information
• Initial support for LAVD CPU scheduler via ‘steamosctl set-cpu-scheduler lavd’