21 env vars · 1 unique to this variant · scraped 28 Jul 2026

NameTypeDescription
PROTON_DEBUG_DIR pathRoot directory for the Proton debug scripts, /tmp by default.
PROTON_DUMP_DEBUG_COMMANDS boolWhen running a game, Proton will write some useful debug scripts for that game into $PROTON_DEBUG_DIR/proton_$USER/.
PROTON_ENABLE_NVAPI boolEnable NVIDIA's NVAPI GPU support library.
PROTON_FORCE_LARGE_ADDRESS_AWARE boolForce Wine to enable the LARGE_ADDRESS_AWARE flag for all executables.
PROTON_HEAP_DELAY_FREE boolDelay freeing some memory, to work around application use-after-free bugs.
PROTON_LOG boolConvenience method for dumping a useful debug log to $HOME/steam-$APPID.log. For more thorough logging, use user_settings.py.
PROTON_NO_D3D10 boolDisables DX10.
PROTON_NO_D3D11 boolDisables DX11.
PROTON_NO_D3D12 boolDisables DX12.
PROTON_NO_D3D9 boolDisables DX9.
PROTON_NO_ESYNC boolDo not use eventfd-based in-process synchronization primitives.
PROTON_NO_FSYNC boolDo not use futex-based in-process synchronization primitives. (Automatically disabled on systems with no FUTEX_WAIT_MULTIPLE support.)
PROTON_NO_WRITE_WATCH boolDisable support for memory write watches in ntdll. This is a very dangerous hack and should only be applied if you have verified that the game can operate without write watches. This improves performance for some very specific games (e.g. CoreRT-based games).
PROTON_NO_XIM uniqueboolEnabled by default. Do not attempt to use XIM (X Input Methods) support. XIM support is known to cause crashes with libx11 older than version 1.7.
PROTON_OLD_GL_STRING boolSet some driver overrides to limit the length of the GL extension string, for old games that crash on very long extension strings.
PROTON_USE_SECCOMP boolEnable seccomp-bpf filter to emulate native syscalls, required for some DRM protections to work.
PROTON_USE_WINED3D boolUse OpenGL-based wined3d instead of Vulkan-based DXVK for d3d11 and d3d10. This used to be called PROTON_USE_WINED3D11, which is now an alias for this same option.
WINE_DO_NOT_CREATE_DXGI_DEVICE_MANAGER boolSet to 1 to enable. Required for video playback in some games to not be miscolored (usually tinted pink)
WINE_FULLSCREEN_FSR boolEnable AMD FidelityFX Super Resolution (FSR) 1, use in conjunction with WINE_FULLSCREEN_FSR_STRENGTH. Only works in Vulkan games (DXVK and VKD3D-Proton included). Enabled by default since GE-Proton7-29
WINE_FULLSCREEN_FSR_CUSTOM_MODE unknownSet fake resolution of the screen. This can be useful in games that render in native resolution regardless of the selected resolution. Parameter WIDTHxHEIGHT
WINE_FULLSCREEN_FSR_STRENGTH unknownAMD FidelityFX Super Resolution (FSR) strength, the default sharpening of 5 is enough without needing modification, but can be changed with 0-5 if wanted. 0 is the maximum sharpness, higher values mean less sharpening. 2 is the AMD recommended default and is set by GE-Proton by default.
Proton Variants v0.4.1 | GitHub