What should CacheSizeMegs be in Killing Floor?

Match it to your RAM: 32 for 256 MB or less, 64 for 512 MB, 128 for 768 MB, and 256 for 1 GB or more. Going above 256 is not recommended.

Why not set CacheSizeMegs higher than 256?

Larger values can make the game crash on some maps with a 'CreateTexture failed' type error, even on PCs with plenty of memory.

Does turning off precaching raise FPS?

It mainly shortens loading and memory use up front. The trade-off is that some assets load the first time they appear, which can cause a short hitch on weaker PCs.

Is Superfetch still a thing on Windows 10 and 11?

Yes, the service is now called SysMain. If you get stuttering, you can stop it and set its startup type to Disabled in services.msc, then test again.

Fixes & Performance

Killing Floor FPS Boost: CacheSizeMegs, Precache and Superfetch

Killing Floor 1 runs on Unreal Engine 2.5 and is very light by modern standards, but its old engine settings can still cause stutter and slow loading. This page covers three tweaks that circulate in the KF community and on Steam: setting the texture cache to fit your RAM, switching off precaching, and disabling Windows Superfetch. For a broader set of INI changes, see Killing Floor optimization (INI tweaks, cache, faster loading) and the complete optimization guide.

About the game

Killing Floor is a first-person co-op shooter with two game types:

Killing Floor mode - survive waves of zombie-like specimens (ZEDs), each wave harder than the last, ending with the boss, the Patriarch.
Objective Mode - adds mission goals on top of the fighting. See the Objective Mode walkthrough.

System requirements

	Minimum	Recommended
CPU speed	1.2 GHz	2.4 GHz
RAM	1 GB	2 GB
OS	Windows XP / Vista	Windows XP / Vista
Video card	64 MB, DirectX 9	128 MB, DirectX 9 with Pixel Shader 2.0
Sound card	Yes	Yes
Disk space	2 GB	2 GB

These are the original launch-era numbers. Any modern PC exceeds them, so if you still get poor performance, the cause is usually configuration, drivers or Windows services, not raw hardware.

Before you edit: find and back up KillingFloor.ini

The file lives in the game's System folder:

Steam\steamapps\common\KillingFloor\System\KillingFloor.ini

In Explorer it shows as a configuration file with a gear icon. Close the game, copy the file somewhere safe, then edit it in Notepad. If you are not sure where your Steam library is, see Killing Floor INI file location.

Tweak 1: match CacheSizeMegs to your RAM

Find the [Engine.GameEngine] section and set CacheSizeMegs based on your memory:

Your RAM	Value
256 MB or less	`CacheSizeMegs=32`
512 MB	`CacheSizeMegs=64`
768 MB	`CacheSizeMegs=128`
1 GB or more	`CacheSizeMegs=256`

Do not go above 256. Bigger values can crash the game on some maps with a texture creation error ("CreateTexture failed"), even if the PC has lots of free memory. The 32-bit engine simply cannot use much more.

Tweak 2: turn off precaching

Precaching loads assets into memory before the map starts. Turning it off shortens the load and lowers the initial memory spike. Change these values, each in its own section:

Section	Change
`[ALAudio.ALAudioSubsystem]`	`UsePrecache=True` to `UsePrecache=False`
`[Engine.LevelInfo]`	`bNeverPrecache=false` to `bNeverPrecache=true`
`[Engine.NullRenderDevice]`	`UsePrecaching=True` to `UsePrecaching=False`
`[D3DDrv.D3DRenderDevice]`	`UsePrecaching=True` to `UsePrecaching=False`
`[D3D9Drv.D3D9RenderDevice]`	`UsePrecaching=True` to `UsePrecaching=False`
`[OpenGLDrv.OpenGLRenderDevice]`	`UsePrecaching=True` to `UsePrecaching=False`
`[PixoDrv.PixoRenderDevice]`	`UsePrecaching=True` to `UsePrecaching=False`

Only the section for the renderer you actually use (usually Direct3D 9) affects play, but changing all of them does no harm. The trade-off: assets that were not preloaded are loaded the first time they appear, so a weak PC may show a brief hitch when a new ZED type spawns. If that bothers you more than the longer load, revert this tweak.

Tweak 3: disable Superfetch (SysMain) if you get stuttering

Superfetch is a Windows service that preloads programs you use often so they start faster. On some systems it was linked to stuttering in Killing Floor. On Windows 7 and Vista it is called Superfetch; on Windows 10 and 11 the same service is named SysMain.

Press Start, type services and open Services.
Find Superfetch (or SysMain) and double-click it.
Set Startup type to Disabled, then click Stop.
Click Apply and OK, then close the window.

Test the game afterwards. If nothing improves, set the service back to Automatic, since it helps general app startup on hard drives.

If FPS is still low

Update or reinstall your GPU driver.
Try borderless or native resolution instead of a scaled one.
Check graphics settings optimization and advanced FPS config.
Crashes on big maps can also be memory-related: see Large Address Aware crash fix.

FAQ

What should CacheSizeMegs be in Killing Floor?: Match it to your RAM: 32 for 256 MB or less, 64 for 512 MB, 128 for 768 MB, and 256 for 1 GB or more. Going above 256 is not recommended.
Why not set CacheSizeMegs higher than 256?: Larger values can make the game crash on some maps with a 'CreateTexture failed' type error, even on PCs with plenty of memory.
Does turning off precaching raise FPS?: It mainly shortens loading and memory use up front. The trade-off is that some assets load the first time they appear, which can cause a short hitch on weaker PCs.
Is Superfetch still a thing on Windows 10 and 11?: Yes, the service is now called SysMain. If you get stuttering, you can stop it and set its startup type to Disabled in services.msc, then test again.