KF2: Unlock FPS Above 150 With Smoothed Frame Rate Settings

Many tweak guides claim to unlock the Killing Floor 2 frame rate, but in practice smoothed FPS stays at 62 and variable FPS at a 150 limit. This short guide, which its author no longer maintains, shows a working way to go above 150 FPS. The game runs on Unreal Engine 3 and the author found no game-breaking issues above 150; only main menu transitions run faster. Companion guides are low-end PC tweaks and less annoying settings.

Smoothed frame rate

Smooth gameplay comes from stable frame times, not from a higher maximum. Dropping suddenly from 144 to 80 FPS feels bad because the frame time jumps from 6.9 ms to 12.5 ms. Frame rate smoothing lets the engine choose an acceptable range between minimum and maximum and cap the frame rate in it for stable frame times. The smoothing commands can be used to allow a higher cap.

How to unlock FPS

The config files are in C:\Users\<USER>\Documents\My Games\KillingFloor2\KFGame\Config. Open KFEngine.ini and KFGame.ini in Notepad++ or similar. Three entries matter:

bSmoothFrameRate=TRUE
MinSmoothedFrameRate=22
MaxSmoothedFrameRate=62

• bSmoothFrameRate: keep it TRUE. Other guides set it to FALSE, which disables smoothing and locks the game to the default 22-62 range (or the 150 FPS variable limit).
• MaxSmoothedFrameRate: the value your FPS is limited to; any number from 30 to 999.

Search for MaxSmoothedFrameRate= in KFEngine.ini. There are two entries; edit the one under [Engine.Engine] and leave [UnrealEd.EditorEngine] alone. For a fully unlocked range:

bSmoothFrameRate=TRUE
MinSmoothedFrameRate=22
MaxSmoothedFrameRate=999

Then open KFGame.ini, search for MaxSmoothedFrameRate= (under [KFGame.KFGameEngine]) and set the same maximum.

Limiting FPS instead

Rather than always chasing the maximum, you might limit FPS for a smoother result:

• Smoothest: use a tool such as Fraps or Frafs to measure your average FPS and cap to it.
• Weak CPU that cannot keep up with the GPU: cap to what the CPU can hold; the default 62 is a good start.
• Screen-tear free: with G-Sync or FreeSync plus V-Sync enabled in the NVIDIA or AMD control panel, set the maximum FPS two frames below the monitor's refresh rate (needs an adaptive sync display).

Bonus: wider FOV

Open KFEngine.ini, search for AspectRatioAxisConstraint=AspectRatio_MaintainXFOV and change X to Y: AspectRatioAxisConstraint=AspectRatio_MaintainYFOV. Save the file and the whole FOV slider gives a wider view.