Vulkan

Stub

This article or section is a stub. You can help by expanding it.

Vulkan is a low-overhead, cross-platform API, open standard for 3D graphics and computing developed by Khronos Group, a successor to OpenGL.

Source exclusively uses Direct3D for rendering and does not support Vulkan. However, as of recent updates, all Valve games (except Alien Swarm) and some third-party games include a built-in copy of DXVK, a library used to translate Direct3D calls to Vulkan. On Windows, this is disabled by default, but can be enabled in supported games by passing -vulkan into the game's launch options, while on Linux (only in Team Fortress 2 branch), it is usually enabled by default.

Source 2 has implemented a native Vulkan renderer, used by default on Linux; it can also be enabled on Windows by passing -vulkan into the game's launch options. Launching the game with Workshop Tools (confirmed on Counter-Strike 2), will always enable Vulkan.

Features

Todo: List all features

Cross-platform (like OpenGL)
Lower CPU usage
Multi-threading friendly design
Raytracing

Vulkan and DXVK notes

Supported operating systems & hardware

On Windows, Vulkan requires Windows 7 or later. Windows 7, 8 and 8.1 support up to Vulkan 1.2. Vulkan 1.3 or later requires Windows 10 or later.
On macOS, Vulkan (and DXVK itself) is not supported by Apple. However MoltenVK can translate Vulkan calls to Metal. MoltenVK is used in Source 2 Mac titles.
On Linux, any Linux distro after 2016 should support it. Linux distros after March 2022 supports Vulkan 1.3, and 2025 for Vulkan 1.4.
For graphics card, Vulkan requires NVIDIA Kepler-based cards (GeForce 600 series) or AMD GCN 1.0 or later.
- Note:NVIDIA Kepler-based and AMD GCN 1.0 - 3.0 cards only support Vulkan 1.2, so some Source/Source 2 games that has newer version of DXVK, which uses Vulkan 1.3 may not work for these cards. Previous version of DXVK (1.10.3) are the last version to support Kepler-based and GCN 1.0 - 3.0 card.
- Vulkan 1.3 and 1.4 is supported on NVIDIA Maxwell-based cards (GeForce 900 series, aswell as 745, 750 and 750Ti) and AMD GCN 4.0 cards.

Bug:On Windows 10 (confirmed on 21H2/LTSC 2021 and 22H2) and Windows 11 (confirmed on 24H2 and 25H2), since January 2026 update, launching games with Vulkan API on Nvidia Maxwell-based graphics card (GeForce 745/750/750 Ti and 900 series) will cause the entire system to hang. This issue is not affected on Pascal (GeForce 10 series) or newer.

Fix:This issue has been fixed in Windows 10 since March 10, 2026 update, and for Windows 11, KB5086672 / March 31, 2026 preview update.

Note:If the problem still occurs, try to revert back to December 2025 update on both Windows 10 and 11 if possible.

OS specific

On Windows, Direct3D is supported natively, so in most cases there is no reason to enable DXVK and doing so may do more harm than good. It should only be used as a last resort to work around graphics driver bugs, or to slightly improve performance on systems which is CPU-limited or games that are poorly optimized.
- For Source 2004 and Source 2006, on system with NVIDIA GPUs, using DXVK will breaks the NVIDIA driver fix, causing fog to be much more dense and makes VGUI element much brighter (which makes certain text less readable).
- Portal 2 in particular is known for having issues with projected textures on various graphics drivers, especially with newer version of graphics drivers: AMD drivers will fail to render all shadows cast by them, while Nvidia drivers will occasionally display static effect which appear on certain materials being hit by one. Enabling DXVK circumvents these issues.
- Using DXVK on Windows will break both windowed mode and borderless window mode, causing it to behave identically to exclusive fullscreen. This "feature" appears to be a part of the graphics drivers themselves and not fixable by the game.
  Workaround:If using an Nvidia graphics card, download Nvidia Profile Inspector and set the option "Buffer-flipping mode" to 0x00000001 OGL_FORCE_BLIT_ON.
- Warning:Also on Windows, some Source engine games such as Half-Life 2 and Portal, due to a bug, the game may run at DirectX 8 level by default on first launch in some hardware. You MUST run the game in DirectX 9.0+ level (dxlevel 95), otherwise using Vulkan with DX8 level will cause graphical glitches and crashes the game.
  Note:To run on DirectX 9 level, use -dxlevel 95 command line argument, then remove it to prevent the game from resetting the graphics settings to default.
- In Black Mesa, since Necro Patch, the game launches in Vulkan instead of Direct3D 9 by default if launched the executable directly. Use -disabledxvk if you don't want this.
On macOS (OS X): For Source 1 titles, DXVK is not supported, due to Vulkan itself not being supported by Apple. Source Engine games on Mac include ToGL (D3D9 to OpenGL) as their only rendering mode. Source 2 on the other hand, ships with MoltenVK, a library that allows Vulkan application and games to run on top of Metal.
On Linux, where Direct3D is not supported, the Source Engine defaults to using Valve's in-house library ToGL to translate Direct3D calls to OpenGL. Using DXVK on Linux is usually recommended if the game supports it, as ToGL is known for having somewhat poor performance, partial support for Shader Model 3, and potentially have graphical issues on some systems.
- On Team Fortress 2 branch games, Vulkan (through DXVK) is enabled by default. To switch back to OpenGL, use -gl command line argument, or select "Legacy OpenGL" when starting the game through Steam (if available).
In all games that support the -gamepadui launch argument, using it will also enable DXVK automatically, including on Windows. Use -dx9 if you don't want this.
- Note:This doesn't apply to Half-Life 2 since 20th Anniversary Update and Portal since May 20, 2025 update, as launching with Gamepad UI now defaults to Direct3D 9. However mods that are built on older version of Gamepad UI may still have this behavior.

Other

Forcing any other anti-aliasing methods (including SGSSAA, and except post-processing like FXAA) is no longer possible, since Vulkan, being a low-level API, bypasses graphics card driver control panel settings. You can still use MSAA with FXAA though to anti-alias foliage and non-alpha to coverage transparent textures, but the result would be inferior compared to SGSSAA.
During first launch, the game may stutter. But after waiting for DXVK to fully cache shaders, there would be less or no stuttering.

Games that support Vulkan

Source (Built-in DXVK)

Half-Life 2 and both Episodes (added since 2022 Steam Deck update)
- Half-Life 2: Lost Coast
- Half-Life 2 RTX (Always used as part of the RTX Remix runtime, then converted to D3D12 (games using DXVK which was then converted again to D3D12 will be shown as "VK/DXGI" in RTSS); Source's copy of DXVK is also included, but attempting to enable it will break rendering.)
Half-Life: Source
Portal (added since 2022 Steam Deck update)
- Portal with RTX (Always used as part of the RTX Remix runtime, then converted to D3D12 (games using DXVK which was then converted again to D3D12 will be shown as "VK/DXGI" in RTSS); Source's copy of DXVK is also included, but attempting to enable it will break rendering.)
Left 4 Dead 2 (since the June 15, 2021 update)
Portal 2 (added in the February 2021 update)
Counter-Strike: Global Offensive (Linux only)
Strata Source (Linux only, enabled by default)
Black Mesa (Xengine)

Bug:Anti-aliasing have issues on objects that are illuminated by new lighting.

Team Fortress 2 (added in April 19, 2024, with the release of 64-bit update)
Half-Life 2: Deathmatch (added in November 16, 2024 with the 20th Anniversary Update)
Counter-Strike: Source (added in February 18, 2025, engine update)
Day of Defeat: Source (added in February 18, 2025, engine update)
Half-Life Deathmatch: Source (added in February 18, 2025, engine update)