FSX uses DirectX, not OpenGL. See which DirectX version FSX and Steam Edition use, what DX10 Preview changes, and which API to choose.
FSX and FSX: Steam Edition use Microsoft DirectX, not OpenGL. Their normal renderer is Direct3D 9, part of DirectX 9, while the optional DirectX 10 Preview switches the simulator to a preliminary Direct3D 10 path. FSX has no built-in OpenGL renderer or menu option for selecting one.
Which DirectX version does FSX use?
FSX uses Direct3D 9 by default, including on computers equipped with DirectX 11- or DirectX 12-capable graphics cards. DirectX is the wider technology family; Direct3D is the graphics API within it.
| FSX mode | Graphics API | Availability | Best use |
|---|---|---|---|
| Standard mode | Direct3D 9 | All FSX versions | Maximum compatibility with aircraft, scenery and graphics add-ons |
| DirectX 10 Preview | Direct3D 10 | Boxed FSX with SP2 or Acceleration, and FSX: Steam Edition | Testing the alternative renderer when installed add-ons support it |
| OpenGL | None | Not available natively | Do not select it for FSX |
FSX does not natively render through Direct3D 11, Direct3D 12, Vulkan or OpenGL. Installing a newer DirectX release does not convert its graphics engine to a newer API.
Should I use DirectX 9 or DirectX 10 Preview?
Use DirectX 9 for the safest add-on compatibility. Choose DirectX 10 Preview only if you want to test its different lighting, shadow and shader behaviour and are prepared to check every important aircraft and scenery package.
- Choose DirectX 9 when older aircraft show missing textures, cockpit elements disappear or scenery objects render incorrectly.
- Try DirectX 10 Preview when your add-ons explicitly support it and you prefer its rendering behaviour on your system.
- Do not choose solely by version number. DX10 Preview is an unfinished alternative renderer, not a complete modernisation of FSX.
Our detailed explanation of the benefits and compatibility problems of FSX DirectX 10 Preview covers that setting separately.
Can FSX be switched to OpenGL?
No configuration edit, launch option or graphics-driver setting can make FSX use OpenGL natively. A compatibility wrapper may translate Direct3D calls behind the scenes, but FSX itself still sends Direct3D instructions and gains no OpenGL option in its menus.
This distinction matters in GPU control panels. OpenGL-specific settings such as OpenGL triple buffering have no effect on FSX; use Direct3D-applicable options instead. Our guide to AMD Radeon settings that actually affect FSX explains which driver controls are relevant.
Which API should I select for ReShade or another graphics tool?
Select the API matching the renderer enabled inside FSX, not the newest API supported by the graphics card.
- For standard FSX rendering, select Direct3D 9.
- With DirectX 10 Preview enabled, select Direct3D 10. Some utility versions group this with later Direct3D APIs.
- Never select OpenGL unless a separate translation wrapper specifically requires it.
- Use the tool's 32-bit build where a choice exists, because FSX and FSX: Steam Edition are 32-bit applications.
Choosing the wrong API is a common reason an injector installs successfully but produces no visible effect. The correct choices and file precautions are covered in our FSX ReShade installation and configuration instructions.
Why does FSX still use DirectX 9 on a modern PC?
FSX keeps using the renderer for which its engine was written, while Windows and the graphics driver provide backward compatibility. A DirectX 12-capable card can therefore run FSX without making FSX a DirectX 12 application.
If FSX reports a missing DirectX component, the problem is usually an absent legacy helper library rather than a lack of modern DirectX support. Repair FSX or reinstall its supplied DirectX prerequisites; simply checking that Windows reports DirectX 12 may not restore the older optional components FSX or an add-on expects.