---
title: "LargeSystemCache 1: what it does, the default value, and whether it helps games"
description: "LargeSystemCache tells the Windows memory manager to favor the file system cache over the memory of running programs. What it changes and how to undo it."
url: https://frozentweaks.com/tweaks/largesystemcache
author: Frost LIVE, Founder of Frozen Tweaks
published: 2026-10-08
updated: 2026-10-08
category: "Memory"
source: Frozen Tweaks (https://frozentweaks.com)
---

# LargeSystemCache 1: what it does, the default value, and whether it helps games

**Short answer:** LargeSystemCache tells the Windows memory manager to favor the file system cache over the memory of running programs. It was designed for file servers. This tweak sets it to 1 and raises IoPageLockLimit. In the registry it sets LargeSystemCache to 1 under HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management, and 1 more value.

## In the app

- Switch: Enable Large System Cache (Memory, Pro, Advanced)
- Undo: Yes. Switching it off sets a standard Windows value, which may not be exactly how you had it.
- Catalog row: https://frozentweaks.com/tweaks#t-1127

## What it does

LargeSystemCache tells the Windows memory manager to favor the file system cache over the memory of running programs. It was designed for file servers. This tweak sets it to 1 and raises IoPageLockLimit.

In the app the switch is called "Enable Large System Cache", described there as: Allocates more RAM for file-system caching to speed up game asset loading (16 GB+ recommended, reboot).

## When it helps

- Loading large game files repeatedly on a PC with plenty of spare memory, where more of them stay cached.

## When it hurts

- On a PC with 16 GB or less, favoring the cache can push a game's own memory out to the page file, which causes exactly the stutter you wanted to avoid.
- Microsoft documents the setting for servers. Some drivers have behaved badly with it in the past.

## What it writes

Read from the app's source. "Switching it off" is what the app writes when you turn the tweak off again.

Registry values:

| Key | Value | With the tweak | Switching it off |
| --- | --- | --- | --- |
| `HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management` | `LargeSystemCache` | `1` | 0 |
| `HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management` | `IoPageLockLimit` | `0x08000000` | 0 |

Source: Tweaks/large_system_cache.hpp in the app's source, app 2.0.0, checked 2026-10-08.

## The same change by hand

Run in a Command Prompt opened as administrator. Make a restore point first.

```bat
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v "LargeSystemCache" /t REG_DWORD /d 1 /f
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v "IoPageLockLimit" /t REG_DWORD /d 0x08000000 /f
```

Put it back:

```bat
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v "LargeSystemCache" /t REG_DWORD /d 0 /f
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v "IoPageLockLimit" /t REG_DWORD /d 0 /f
```

See what it is set to now:

```bat
reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v "LargeSystemCache"
```

## How to undo it

Switch the tweak off in Frozen Tweaks. It writes LargeSystemCache back to 0, IoPageLockLimit back to 0.

## Verdict

Marginal at best on a gaming PC, and a risk with little memory. Use it only with 32 GB or more, and measure.

## Questions

### What does the "Enable Large System Cache" tweak change in Windows?

In the registry it sets LargeSystemCache to 1 under HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management, and 1 more value. The full list is in the table on this page, read from the app's source.

### What is the standard value of LargeSystemCache?

Frozen Tweaks writes 0 when you switch the tweak off, which is the value it treats as the Windows standard. With the tweak on, LargeSystemCache is 1.

### Is "Enable Large System Cache" safe to switch on?

Marginal at best on a gaming PC, and a risk with little memory. Use it only with 32 GB or more, and measure. The main cost: On a PC with 16 GB or less, favoring the cache can push a game's own memory out to the page file, which causes exactly the stutter you wanted to avoid.

### How do I undo it?

Switch the tweak off in Frozen Tweaks. Switching it off sets a standard Windows value, which may not be exactly how you had it.

### Does it need a restart?

Yes, the change applies after a restart.

### Is "Enable Large System Cache" free in Frozen Tweaks?

It is part of Frozen Pro and Elite. You can also make the change by hand with the values on this page.

## Related guides

- [How to Fix Stuttering and Frame Drops: Diagnose Before You Tweak](https://frozentweaks.com/guides/fix-stuttering-frame-drops)

## More tweak explainers

- [DisablePagingExecutive](https://frozentweaks.com/tweaks/disablepagingexecutive)
- [Memory compression](https://frozentweaks.com/tweaks/disable-memory-compression)
- [NVMe interrupt steering](https://frozentweaks.com/tweaks/nvme-interrupt-steering)

---
Written by Frost LIVE, founder of Frozen Tweaks. Canonical version: https://frozentweaks.com/tweaks/largesystemcache