SpecialK is required for the main version of the mod. A slightly worse version is available that doesn't use Special K's framelimiter.
We recommendusing Special K for this game, though. It really fixes a LOT of performance issues.

You will need Kaldaien's Special K injectable in order to fix some of other game issues such as enforced V-Sync and window/thread sleeps:
https://discourse.differentk.fyi/ or special build for Replicant (recommended) available on Discord server https://discord.com/invite/ER4EDBJPTa in #nier-replicant channel.
To install SK as local injectable extract SpecialK64.dll into game folder and rename it as dxgi.dll or dinput8.dll.

Possibly helpful SpecialK settings:

• In game press Ctrl+Shift+Backspace to toggle SK settings overlay then enable framerate limit and set it to your desired cap value, in advanced settings make sure sleepless window and render thread boxes are checked.
• Under Direct 3D 11 settings, enable Use Flip Model Presentation and set Presentation Interval to 0 in order to disable V-Sync.
  

For best results though, you should check Special K discord for the latest Special K versions and suggested settings.

Do NOT enable High Dynamic Framerate option in Special K if using this.


Extract into the game directory (steamapps\common\NieR Replicant ver.1.22474487139\), where the game .exe is located.

If you're using Special K, you should use Special K's import dll function. Extract high_fps.dll into the game directory and add this to the bottom of Special K's config file:

[Import.HighFPS]
Architecture=x64
Role=ThirdParty
When=Early
Filename=high_fps.dll

If you aren't using Special K (why?), just extract dinput8.dll into the game directory.


If you are using modified executable (like ultrawide patches, etc) launch the game with -skipcheck startup parameter to disable version check.
Please note that disabling version check will allow you to run the mod on unsupported versions of the game which may produce even less stable behavior than by default.



• Main menu FPS is capped to 60 because of the loadscreen workaround.
• "Boar drifting" causes the boar to lunge unintentionally long distances.
  

If your gamepad stops working, and you're using Special K:
Inside dinput8.ini set DisablePS4HID=false under [Input.Gamepad]



The game outright refuses to use 100% of the GPU even with V-Sync disabled, Special K is very much recommended in order to achieve reliable 120/144+ FPS on most gaming hardware.

Additionally the game will occasionally fail to load environment presets properly at high framerates (regardless whether the fix is installed or not).
The fix mitigates this issue greatly by forcing approximate 60 FPS cap during loading screens. Please note that it is very likely that the issue can still occur even at flat capped 60 FPS and its severity just increases with framerate due to some bad race condition in some of the functions ran during loading.

Also please note that this is an injectable modification that patches memory of the game at runtime, it can and most likely will break with subsequent game updates.



Simply remove the dinput8.dll / high_fps.dll.