If you haven't modified the game in any way, chances are you're playing on Vulkan API and should ignore this guide.

This guide tackles a very niche problem -- for a very specific audience, who would like to use D3D11 API, keep steam overlay working, and maintain the advantages of Fullscreen mode.

Switching to D3D11 mainly benefits in getting better input latency.

Instructions:
- Right click on your game in Steam
- Select Properties
- In Launch options, add following text:
If you have performance issues, try adding +r_gpuCulling 0 as well.

Here's the thing. Running in D3D11 and in Fullscreen mode disables alt-tabbing and makes steam overlay inaccessible for whatever reason. This guide will provide solutions and workarounds for this issue.

One of the solutions is to simply switch to borderless mode.

- steam overlay works
- alt-tab works
- easy to setup

- added input latency
- forced vsync on

- Navigate to Options -> Display -> Open video settings...
- Set Window mode to Borderless

- steam overlay works
- low input latency
- vsync can be disabled
- glassfloor frametimes

- pain-in-the-butt to setup
- alt-tab still doesn't work in fullscreen

1. Download SpecialK
- Official release: website link[discourse.differentk.fyi]
- Latest experimental release (recommended): Discord link[discord.gg]
2. Extract SpecialK64.dll into ...\Quake\rerelease\ directory
3. Rename SpecialK64.dll into d3d11.dll
4. Launch the game
5. Temporarily switch to Borderless mode
6. Press Ctrl+Shift+Backspace shortcut -- this will bring up SK overlay
7. Setup your preferences similar to these: image link[i.imgur.com]

7.1) Navigate to Framerate limit -> Advanced
- (optional) Enable framerate limit
- Low Latency Mode: on
- NV Reflex: minimal
7.2) Navigate to D3D11 settings -> ChainSwap Management
- Use FlipModel presentation: on
- Waitable ChainSwap: on
- Enable DWM tearing: on
- BackBuffer count and Max device latency: 1 or 2
7.3) Navigate to On screen display
- (optional) Set timer to 0.0 seconds

8. (optional) Switch back to Fullscreen mode
9. Restart the game
10. You're good to go here.

Note: Fullscreen optimizations are recommended to be left enabled. If this doesn't tell you anything, ignore this.

If you really want to keep v-sync enabled, it's recommended to do some adjustments.

1. For g-sync/freesync owners: set framerate limit slightly below refresh rate (e.g. 141 at 144hz).
Otherwise, if your FPS exceeds your HZ, the g-sync will turn off and regular v-sync might kick in, resulting in excessive input lag.

2. For regular displays: you can actually try setting up a low-lag v-sync (similar to g-sync). The only requirement will be maintaining extremely stable fps and having a precise framerate cap.

For that, generally refer to this blurbusters article[blurbusters.com]
You can also use SpecialK's fps limiter instead of RTSS (it's just as good), just make sure your frametimes graph remains FLAT at all times! Example[i.imgur.com]