What is the difference between DX11 and DX9?

DirectX 11 support arrived with the January 17, 2024 maintenance. DX9 was not removed, so you can still pick either one in Option. What changes is the list of graphics settings you get: DX11 has the newer effects, DX9 keeps the classic quality steps. Terrain View, the blur effect and Lowest Spec Mode are shared by both.

Graphics settings available in DX11 and DX9
SettingDX11DX9
Shadows X / Low / Dynamic Shadows (real-time) X / Low / Mid / High
Textures Enable Texture Enhancement, Terrain Texture Enhancement Use Shader Effect, Terrain Texture Quality
Water Use water reflection River, Lake Quality: Low / Mid / High
Picture Brightness, 3D Clarity Improvement, Color Analysis Filter None
Shared Terrain View, Blur Effect, Lowest Spec Mode Terrain View, Blur Effect, Lowest Spec Mode

DX11 or DX9: which one should you use?

Picking DirectX for your situation
Your situationPick
Your GPU supports DX11 and the game runs fine DX11
DX11 crashes, freezes, goes black or shows broken graphics DX9, then restart the game
You want the colorblind filter or the brightness slider DX11 (DX9 doesn't have them)
Your integrated graphics can't run DX9 The game moves you to DX11 automatically

DX11 has kept getting fixes since it launched: the January 2024 patch listed the FPS drops in Moradon and Ronark Land among its DX11 fixes, and the August 2025 patch added DirectX 11 performance improvements on top. If nothing is wrong on your PC, DX11 should be your default.

How do you switch between DX11 and DX9?

  1. With the game closed: open Option.exe in your Knight Online folder, tick DX11 or DX9 under DX Option, then hit Save Changes and Start.
  2. In game: go to Option > Graphic option > DirectX Option, pick DirectX 11 or DirectX 9 and press APPLY.
  3. The switch doesn't always apply cleanly on the spot; if the picture looks off, close the game and start it again.
Knight Online Game Option Setup window: DX11 and DX9 choice under DX Option with shadow, water and texture settings; Visibility Range, Terrain View and resolution below
Knight Online Game Option Setup
Source / rights
Image / usage information: Knight Online — Mgame / NTTGame.

Most stable DX11 settings

There is no single stable setup that works for everyone; a setting that runs smoothly on one PC can stutter on another. The reliable approach is to start from the bottom and turn things on one at a time:

  1. Press Lowest Spec Mode in the DirectX Option window, then APPLY. It drops every related setting to its lowest and pushes speed to the maximum.
  2. If the game runs smoothly, turn on Enable Texture Enhancement first. With it off, Reverse items can look dull in DX11.
  3. Next, set Use Shadows to Low. Dynamic Shadows calculates shadows in real time from light and movement, so it is the first thing to turn off when you start lagging.
  4. Leave Use water reflection, Terrain Texture Enhancement and 3D Clarity Improvement for last; they make the game prettier but don't help you play.
  5. After each change, spend a few minutes somewhere busy, like Moradon or a war zone, and turn the setting back off if it causes trouble.

Most stable DX9 settings

Same order on DX9: start with Lowest Spec Mode, then raise these one by one.

  • Use Shader Effect: keep it on, because some effects don't work with shaders off. Try turning it off only if the game crashes.
  • Shadow Quality: start at Low. X turns shadows off, Low uses a simple fixed shadow, and Mid and High draw them in more detail.
  • River, Lake Quality: Low is the most basic water, Mid adds movement, High is the most detailed.
  • Terrain Texture Quality: adds light-reactive textures to the ground; turn it off on a weak GPU.
  • Terrain View: on Low only nearby ground is drawn in detail, on High distant ground too. It's one of the first settings to lower when you stutter.

FAQ

Is DX11 better than DX9 in Knight Online?
DX11 looks better and gets all the new effects. Stability depends on your PC, and for anyone having trouble on DX11 the quickest fix is switching to DX9.
How do I fix a DirectX 9 error in Knight Online?
If the game says a file starting with d3dx9 is missing, run dxwebsetup.exe from your Knight Online folder to install the DirectX runtime files. If the error stays, try DX11.
Why don't my Reverse items glow in DX11?
Check the Item Glow Effect box in Graphic option first; if it's unticked, you won't see the glow at all. If it's ticked and the glow still looks weak, turn on Enable Texture Enhancement in DirectX Option.
Where is the colorblind mode?
Switch to DX11 and pick Red, Green or Blue under Color Analysis Filter in DirectX Option. The filter and the brightness setting were added in May 2024 and aren't available on DX9.

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