---
title: "FeatureSettingsOverride 3: disabling Spectre and Meltdown mitigations for performance"
description: "The Spectre and Meltdown mitigations are processor security fixes that cost some performance, mostly on older processors. What it changes and how to undo it."
url: https://frozentweaks.com/tweaks/disable-spectre-meltdown-mitigations
author: Frost LIVE, Founder of Frozen Tweaks
published: 2026-10-08
updated: 2026-10-08
category: "Security"
source: Frozen Tweaks (https://frozentweaks.com)
---

# FeatureSettingsOverride 3: disabling Spectre and Meltdown mitigations for performance

**Short answer:** The Spectre and Meltdown mitigations are processor security fixes that cost some performance, mostly on older processors. FeatureSettingsOverride and FeatureSettingsOverrideMask set to 3 switch the main mitigations off. In the registry it sets FeatureSettingsOverride to 3 under HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management, and 1 more value.

## In the app

- Switch: Disable Spectre/Meltdown Mitigations (Security, 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-1074

## What it does

The Spectre and Meltdown mitigations are processor security fixes that cost some performance, mostly on older processors. FeatureSettingsOverride and FeatureSettingsOverrideMask set to 3 switch the main mitigations off.

In the app the switch is called "Disable Spectre/Meltdown Mitigations", described there as: Removes kernel mitigations for raw performance (security trade-off, reboot).

## When it helps

- Older Intel processors (roughly 2019 and before), where the mitigations have a measurable cost in processor-bound games.

## When it hurts

- The PC is open to a known class of attacks again, including from websites.
- On recent processors the fixes are built into the hardware and the gain is close to zero.
- Some anti-cheat systems may object to missing mitigations.

## 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` | `FeatureSettingsOverride` | `3` | 0 |
| `HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management` | `FeatureSettingsOverrideMask` | `3` | 0 |

Source: Tweaks/perf_mitigations_off.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 "FeatureSettingsOverride" /t REG_DWORD /d 3 /f
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v "FeatureSettingsOverrideMask" /t REG_DWORD /d 3 /f
```

Put it back:

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

## How to undo it

Switch the tweak off in Frozen Tweaks. It writes FeatureSettingsOverride back to 0, FeatureSettingsOverrideMask back to 0.

## Verdict

A security trade we would only consider on an old processor, on a PC used for games and nothing sensitive.

## Questions

### What does the "Disable Spectre/Meltdown Mitigations" tweak change in Windows?

In the registry it sets FeatureSettingsOverride to 3 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 FeatureSettingsOverride?

Frozen Tweaks writes 0 when you switch the tweak off, which is the value it treats as the Windows standard. With the tweak on, FeatureSettingsOverride is 3.

### Is "Disable Spectre/Meltdown Mitigations" safe to switch on?

A security trade we would only consider on an old processor, on a PC used for games and nothing sensitive. The main cost: The PC is open to a known class of attacks again, including from websites.

### 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 "Disable Spectre/Meltdown Mitigations" 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

- [Is PC Optimization Software Safe? What to Check Before Installing](https://frozentweaks.com/guides/is-pc-optimization-software-safe)
- [Windows 11 Gaming Optimization: What Still Works in 2026](https://frozentweaks.com/guides/windows-11-gaming-optimization)

## More tweak explainers

- [Defender exclusions for games](https://frozentweaks.com/tweaks/defender-exclusions-for-games)
- [Remote Desktop Services (TermService)](https://frozentweaks.com/tweaks/disable-remote-desktop-services)
- [Location access](https://frozentweaks.com/tweaks/disable-location-tracking)

---
Written by Frost LIVE, founder of Frozen Tweaks. Canonical version: https://frozentweaks.com/tweaks/disable-spectre-meltdown-mitigations