PROTON_LOG Writes a Proton and Wine debug log to $HOME/steam-<appid>.log. PROTON_LOG=1 enables the de1940 threadsPROTON_USE_WINED3D Replaces DXVK with WineD3D, translating Direct3D to OpenGL instead of Vulkan. Used to work729 threadsWINEPREFIX Path to the Wine prefix, the virtual C: drive. Proton manages its own prefix per game unde516 threadsWINEDLLOVERRIDES Tells Wine whether to load the native (Windows) or built-in (Wine) version of a DLL, for e443 threadsVKD3D_CONFIG Comma-separated switches for vkd3d-proton, the Direct3D 12 layer. Common values include dx442 threadsWINEDEBUG Selects Wine debug channels, for example WINEDEBUG=+timestamp,+seh,+loaddll. Adds detail t432 threadsPROTON_NO_ESYNC Disables esync, Proton's eventfd-based synchronisation. Set to 1 when a game deadlocks or 365 threadsDXVK_HUD Draws DXVK's overlay with frame rate, driver and device information. DXVK_HUD=1 shows the 333 threadsPROTON_NO_FSYNC Disables fsync, the futex-based synchronisation path. Set to 1 to fall back to esync or to206 threadsRADV_DEBUG Debug switches for Mesa's RADV Vulkan driver on AMD, such as RADV_DEBUG=nohiz or zerovram,205 threadsPROTON_ENABLE_NVAPI Enables DXVK-NVAPI so games can see NVIDIA features such as DLSS and Reflex while running 200 threadsRADV_PERFTEST Enables experimental RADV features, for example RADV_PERFTEST=gpl for the graphics pipelin167 threadsPROTON_ENABLE_WAYLAND Runs the game on Proton's native Wayland backend instead of XWayland. Experimental, and ne157 threadsPROTON_USE_WINED3D11 Older switch that forced WineD3D for Direct3D 11 only. It is superseded by PROTON_USE_WINE152 threadsMANGOHUD Runs the game with the MangoHud overlay showing frame rate, frame times and sensors. Usual142 threadsPROTON_HIDE_NVIDIA_GPU Hides the NVIDIA GPU from the game. Some launchers and anti-cheat modules handle NVIDIA ha138 threadsDXVK_LOG_LEVEL Controls how much DXVK logs: none, error, warn, info or debug.133 threadsDXVK_FILTER_DEVICE_NAME Restricts DXVK to a GPU whose name contains the given text, which matters on hybrid laptop131 threadsSTEAM_COMPAT_DATA_PATH Directory Proton uses for the game's prefix and state. It is required when running Proton 131 threadsVKD3D_DEBUG Sets vkd3d-proton's log level, for example VKD3D_DEBUG=warn or none.127 threadsPROTON_USE_D9VK Historic switch that enabled D9VK for Direct3D 9. D9VK was merged into DXVK, so current Pr121 threadsPROTON_FORCE_LARGE_ADDRESS_AWARE Lets 32-bit games use more than 2 GB of address space. It is enabled by default in modern 119 threadsDXVK_CONFIG Sets DXVK tunables inline, for example DXVK_CONFIG="dxgi.maxDeviceMemory = 4096".114 threadsVKD3D_FEATURE_LEVEL Reports a specific Direct3D 12 feature level to the game, for example VKD3D_FEATURE_LEVEL=112 threadsVKD3D_DISABLE_EXTENSIONS Disables named Vulkan extensions in vkd3d-proton, such as VK_EXT_mesh_shader when a driver107 threadsDXVK_ASYNC Enables asynchronous pipeline compilation to reduce shader stutter. It is absent from upst103 threadsPROTON_NO_D3D11 Disables DXVK's d3d11 so the game falls back to WineD3D or an older renderer.97 threadsWINE_CPU_TOPOLOGY Presents a different CPU topology to the game, for example WINE_CPU_TOPOLOGY=8:0,1,2,3,4,595 threadsDXVK_FRAME_RATE Caps the frame rate inside DXVK, for example DXVK_FRAME_RATE=60.94 threadsLD_PRELOAD Preloads a shared library into the game process. Used for overlays and shims, and sometime93 threadsSDL_VIDEODRIVER Chooses SDL's video backend, x11 or wayland. Often set to x11 to work around Wayland curso90 threadsPROTON_DUMP_DEBUG_COMMANDS Writes helper scripts to /tmp/proton_$USER/ for running winedbg and other tools inside the86 threadsWINEARCH Selects a 32-bit (win32) or 64-bit (win64) prefix. Proton manages this itself.84 threadsVK_ICD_FILENAMES Points the Vulkan loader at a specific driver manifest, which forces a particular GPU or d77 threadsSDL_GAMECONTROLLERCONFIG Supplies an SDL controller mapping string for a pad that is unrecognised out of the box.74 threads__NV_PRIME_RENDER_OFFLOAD Runs the game on the discrete NVIDIA GPU on hybrid systems, normally together with __GLX_V73 threadsDRI_PRIME69 threadsSTEAM_COMPAT_CLIENT_INSTALL_PATH Path to the Steam client installation. Proton needs it when it is launched outside of Stea69 threadsDXVK_CONFIG_FILE Points DXVK at a configuration file holding tunables such as dxvk.maxFrameLatency or dxgi.67 threadsPROTON_DISABLE_NVAPI Disables DXVK-NVAPI, and with it DLSS, when NVAPI causes crashes or launcher problems.63 threadsSDL_AUDIODRIVER Selects SDL's audio backend: pulseaudio, pipewire or alsa.61 threads__GLX_VENDOR_LIBRARY_NAME61 threadsWINEFSYNC55 threadsPULSE_LATENCY_MSEC Raises the PulseAudio buffer latency to fix crackling audio, for example PULSE_LATENCY_MSE53 threadsWINEESYNC53 threadsPROTON_SET_GAME_DRIVE Maps the game's library folder to a drive letter (S:) inside the prefix, which some games 48 threadsDXVK_HDR45 threadsNVIDIA45 threads__GL_SHADER_DISK_CACHE_SKIP_CLEANUP44 threadsPROTON_ENABLE_HDR43 threadsSDL_G43 threadsPROTON_LOG_DIR Directory the Proton log is written to instead of $HOME.42 threads__GL_THREADED_OPTIMIZATIONS42 threadsMESA_VK_DEVICE_SELECT Selects which Vulkan device Mesa exposes, given as a vendorID:deviceID pair, for multi-GPU41 threadsVKD3D_SHADER_DEBUG36 threadsPROTON_USE_NTSYNC35 threadsPROTON_ENABLE_NGX_UPDATER34 threadsVKD3D_SHADER_CACHE34 threadsWINE_LARGE_ADDRESS_AWARE Wine's own large address aware switch for 32-bit games, equivalent to Proton's forcing opt34 threadsMESA_LOADER_DRIVER_OVERRIDE33 threadsPROTON_VKD3D_HEAP33 threadsENABLE_VKBASALT Turns on vkBasalt post-processing effects such as sharpening for Vulkan games.32 threads__GL_SHADER_DISK_CACHE_PATH32 threadsDXVK_ENABLE_NVAPI31 threadsWINE_DO_NOT_CREATE_DXGI_DEVICE_MANAGER31 threadsSDL_VIDEO_MINIMIZE_ON_FOCUS_LOSS29 threadsUTF29 threadsDXVK_STATE_CACHE Controls DXVK's pipeline state cache, which is what keeps shader stutter down between runs28 threadsPROTON_NO_NTSYNC28 threadsPROTON_USE_SECCOMP Enables Proton's seccomp filter, which some anti-cheat and DRM implementations require.28 threadsRADV28 threadsSDL_I28 threadsDXVK_LOG_PATH27 threadsVKD3D_SHADER_MODEL Caps the shader model vkd3d-proton reports, for example VKD3D_SHADER_MODEL=6_5.27 threads__GL_SHADER_DISK_CACHE27 threadsWINE_FULLSCREEN_FSR Enables AMD FidelityFX Super Resolution upscaling for fullscreen games running under Proto26 threadsPROTON_ENABLE_HIDRAW25 threadsSDL_GAMECONTROLLER_IGNORE_DEVICES24 threadsLC_ALL23 threadsSTEAM_COMPAT_APP_ID23 threads__GL_SHADER_DISK_CACHE_SIZE23 threadsDXVK_DEBUG_LAYERS21 threadsPROTON_DXVK_D3D821 threadsPROTON_USE_XALIA21 threadsSTEAM_COMPAT_MOUNTS21 threadsVKD3D_FILTER_DEVICE_NAME21 threadsMESA_GL_VERSION_OVERRIDE20 threadsPROTON_FSR4_UPGRADE20 threadsVKD3D_LOG_FILE20 threadsVKD3D_SHADER_DUMP_PATH20 threadsAMD_VULKAN_ICD19 threadsPROTON_PREFER_SDL19 threadsVKD3D_FRAME_RATE19 threadsMANGOHUD_CONFIG18 threadsVKD3D_SHADER_CACHE_PATH18 threadsPROTON_FORCE_NVAPI17 threadsPROTON_NO_D3D1017 threadsSDL_V17 threadsDXVK_SHADER_DUMP_PATH16 threadsPROTON_DLSS_UPGRADE16 threadsSDL_JOYSTICK_DEVICE16 threadsSDL_VIDEO_DRIVER16 threadsVKD3D_VULKAN_DEVICE16 threadsDXVK_STATE_CACHE_PATH15 threadsPROTON_USE_DXVK15 threadsPROTON_USE_WAYLAND15 threadsWINE_MONO_OVERRIDES15 threadsDXVK_NVAPI_LOG_LEVEL14 threadsENABLE_HDR_WSI14 threadsPROTON_OLD_GL_STRING Reports a shorter, older OpenGL version string for games that parse it badly.14 threadsPROTON_USE_WOW6414 threadsSDL_C14 threadsSDL_JOYSTICK_HIDAPI14 threadsSDL_S14 threads__GL_N14 threadsDXVK_FAKE_DX10_SUPPORT13 threadsQT_QPA_PLATFORM13 threadsVK_DRIVER_FILES13 threadsVK_INSTANCE_LAYERS13 threadsWINE_SIMULATE_WRITECOPY13 threadsMESA_GLSL_CACHE_DIR12 threadsPROTON_HEAP_DELAY_FREE Delays heap frees to work around use-after-free bugs in some games.12 threadsPROTON_VERSION12 threadsDXVK_DEBUG11 threadsPROTON_EAC_RUNTIME11 threadsSTEAM_COMPAT_INSTALL_PATH11 threadsUSEALLAVAILABLECORES11 threadsUSERNAME11 threadsWINE_D3D_CONFIG11 threadsDXVK_NVAPI10 threadsMESA_EXTENSION_MAX_YEAR10 threadsPROTON_DISABLE_HIDRAW10 threadsRADV_EXPERIMENTAL10 threadsSDL_VIDEO_X11_DGAMOUSE10 threadsSTEAM_COMPAT_TOOL_PATHS10 threadsWINE_HIDE_NVIDIA_GPU10 threads__GL_YIELD10 threadsDISPLAY9 threadsDXVK_NVAPI_GPU_ARCH9 threadsHOST_LC_ALL9 threadsLIB9 threadsMESA_SHADER_CACHE_MAX_SIZE9 threadsPROTON_ENABLE_AMD_AGS9 threadsSDL_INIT_AUDIO9 threadsSTEAM_COMPAT_SESSION_ID9 threadsVKD3D_SHADER_OVERRIDE9 threadsVKD3D_TEST_FILTER9 threadsWINE_DISABLE_HARDWARE_SCHEDULING9 threadsWINE_FULLSCREEN_FSR_STRENGTH9 threads__GL_M9 threads__GL_THREADED_OPTIMIZATION9 threadsDXVK_NVAPI_DRIVER_VERSION8 threadsDXVK_SHADER_READ_PATH8 threadsENABLE_GAMESCOPE_WSI8 threadsGA1008 threadsMESA_GLSL_VERSION_OVERRIDE8 threadsMESA_VK_WSI_PRESENT_MODE8 threadsPROTON_BATTLEYE_RUNTIME8 threadsPROTON_DEBUG_DIR8 threadsPROTON_LOGS8 threadsPROTON_NO_STEAMINPUT8 threadsPROTON_USE_SDL8 threadsPROTON_USE_WINE3D8 threadsSDL_IM_MODULE8 threadsSDL_J8 threadsSDL_W8 threadsUSLEEP8 threadsVKD3D_SWAPCHAIN_LATENCY_FRAMES8 threadsAPPID7 threadsDXVK_NVAPI_ALLOW_OTHER_DRIVERS7 threadsDXVK_NVAPI_DISABLE_ENTRYPOINTS7 threadsDXVK_SHADER_OPTIMIZE7 threadsLD_LIBRARY_PATH7 threadsMESA_SHADER_CACHE_DIR7 threadsMESA_SHADER_CACHE_DISABLE7 threadsPROTON_NO_D3D127 threadsPROTON_NO_WM_DECORATION7 threadsPROTON_USE_EAC_LINUX7 threadsPYROVEIL7 threadsPYROVEIL_CONFIG7 threadsSDL_AUDIO_CHANNELS7 threadsSTEAM_COMPAT_LIBRARY_PATHS7 threadsSTEAM_COMPAT_RUNTIME_SDL27 threadsWINE_FULLSCREEN_INTEGER_SCALING7 threads__GL_E7 threadsDXVK_NVAPI_VKREFLEX6 threadsLFX6 threadsPRESSURE_VESSEL_FILESYSTEMS_RW6 threadsPROTON_CRASH_REPORT_DIR Directory Proton writes crash reports into, which is useful when attaching them to a bug r6 threadsPROTON_MEDIA_USE_GST6 threadsSDL_D6 threadsSDL_H6 threadsSTEAM_COMPAT_SHADER_PATH6 threadsVKD3D_QUEUE_PROFILE6 threads__GL_SHADER_DISK_CACHE_APP_NAME6 threads__GL_SYNC_TO_VBLANK6 threadsDXVK_CUSTOM_VENDOR_ID5 threadsDXVK_FEATURE_LEVEL5 threadsDXVK_WSI_DRIVER5 threadsGST_PLUGIN_FEATURE_RANK5 threadsMESA_DEBUG5 threadsMESA_DISK_CACHE_READ_ONLY_FOZ_DBS5 threadsMESA_GLSL_CACHE_MAX_SIZE5 threadsPROTON_AUDIO_CONVERT_BIN5 threadsPROTON_LOCAL_SHADER_CACHE5 threadsPROTON_NO_XIM Disables the X input method, which can fix stuck keys and broken text entry in some games.5 threadsPROTON_USE_NVAPI5 threadsPROTON_USE_VKD3D5 threadsPROTON_VKD3D_LOWLATENCY5 threadsSDL25 threadsSDL_DYNAMIC_API5 threadsSDL_GAMECONTROLLER_USE_BUTTON_LABELS5 threadsSDL_O5 threadsSDL_P5 threadsSDL_Q5 threadsSTEAMDECK5 threadsSTEAM_COMPAT_CONFIG5 threadsWINEFSYNC_FUTEX25 threadsWINE_DEFAULT_DEBUG_CHANNEL5 threadsWINE_DISABLE_VULKAN_OPWR5 threadsWINE_MONO_TRACE5 threadsXMODIFIERS5 threadsYOUR5 threadsAMD_DEBUG4 threadsDISABLE_LAYER_MESA_ANTI_LAG4 threadsDXVK_FILTER_DEVICE_UUID4 threadsDXVK_NVAPI_DRS_SETTINGS Overrides NVIDIA driver settings through DXVK-NVAPI, such as forcing DLSS behaviour.4 threadsDXVK_SPIRV_OPT4 threadsDXVK_USE_PIPECOMPILER4 threadsGST_DEBUG4 threadsMESA_DISK_CACHE_SINGLE_FILE4 threadsMESA_NO_ERROR4 threadsMESA_VK_VERSION_OVERRIDE4 threadsNONE4 threadsPROTON_AUDIO_CONVERT4 threadsPROTON_CONFIG4 threadsPROTON_DEMUX4 threadsPROTON_FSR4_RDNA3_UPGRADE4 threadsPROTON_NO_GLSL4 threadsPROTON_PRIORITY_HIGH4 threadsPROTON_REMOTE_DEBUG_CMD4 threadsPROTON_USE_GALLIUM_NINE4 threadsPROTON_USE_WINE3D114 threadsPROTON_USE_WINE_DXGI4 threadsPROTON_VIDEO_CONVERT4 threadsSDL_A4 threadsSDL_INIT_VIDEO4 threadsSDL_JOYSTICK_WHEEL_DEVICES4 threadsSDL_WINDOWEVENT_FOCUS_GAINED4 threadsSDL_WINDOWEVENT_RESIZED4 threadsSTEAM4 threadsSTEAMAPPS4 threadsSTEAMROOT4 threadsSTEAM_COMPAT_TRANSCODED_MEDIA_PATH4 threadsVSYNC4 threadsWINDLLOVERRIDES4 threadsWINE_GST_REGISTRY_DIR4 threadsWINE_LAYERED_OVERLAY_ALPHA4 threads__GL_CONSTANT_FRAME_RATE_HINT4 threads