Performance Issue Fortnite

Fortnite FPS Drops After December 20th - Complete Fix Guide

📅 Published: 2026-02-06 🔄 Updated: 2026-02-06 👥 Reports: 4 ⚡ Severity: 🟢 Low

🎯 Quick Answer

Disable the Windows 11 24H2 update's "Core Isolation > Memory Integrity" feature, as it conflicts with Fortnite's anti-cheat following a game update on December 20th, 2025.

SECTION 1: OVERVIEW

The error is defined as severe, periodic frame rate drops in Fortnite, occurring specifically after the game update on December 20th, 2025. The issue manifests on the Windows platform, affecting both Windows 10 and Windows 11, with a higher incidence rate on systems that have recently received the Windows 11 24H2 feature update. The problem occurs in all game modes and persists regardless of graphical settings or resolution changes. This is a common issue with a high severity impact, rendering the game unplayable due to frames per second (FPS) dropping below 20 at regular intervals. No specific error codes are generated; the failure is observed as a performance degradation within the game engine and audio subsystem.

SECTION 2: SYMPTOMS

The application experiences severe frame time inconsistency and GPU utilization drops during standard gameplay. The frame rate plummets from a stable high value to below 20 FPS at intervals of several seconds. Concurrent with the FPS drop, the audio stream terminates or stutters. The issue initiates upon loading into a match and continues persistently. The system exhibits normal performance metrics in other GPU-intensive applications and synthetic benchmarks. Task Manager or performance monitoring software shows anomalous dips in the 3D GPU usage graph for Fortnite specifically during these episodes.

SECTION 3: COMMON CAUSES

Category: Software Conflict Specific technical explanation: The Windows 11 24H2 update enables "Memory Integrity" (a Core Isolation feature) by default on many new systems. This hypervisor-protected code integrity (HVCI) feature conflicts with the kernel-level drivers used by Fortnite's anti-cheat software (Easy Anti-Cheat or BattleEye), causing severe scheduling delays and performance hits. Why this causes the problem: The anti-cheat driver's required low-level hardware access is intercepted and virtualized, creating significant overhead that manifests as frame time spikes and audio buffer underruns. Category: Game Bug Specific technical explanation: The Fortnite update deployed on December 20th, 2025, introduced a change to the shader compilation pipeline or streaming logic that is incompatible with certain GPU driver versions or Windows subsystem versions. Why this causes the problem: Inefficient or repeated shader compilation during gameplay causes the rendering thread to stall, leading to immediate frame drops and audio processing interruptions tied to the same game thread. Category: Configuration Error Specific technical explanation: The game's user configuration files, particularly those governing rendering mode (DirectX 12 vs. Performance Mode), become corrupted or contain invalid parameters post-update. Why this causes the problem: The game engine attempts to execute an unsupported or broken rendering path, forcing fallback procedures that cannot maintain consistent performance. Category: Software Conflict Specific technical explanation: Out-of-date or corrupted Microsoft Visual C++ Redistributables or DirectX End-User Runtime files required by the updated game binary. Why this causes the problem: The game engine fails to load critical graphics or system libraries efficiently, causing runtime linking delays that stall the main thread. Category: Configuration Error Specific technical explanation: A power management setting, either in Windows (e.g., Ultimate Performance plan not active) or the GPU control panel (e.g., Power Saving mode), is incorrectly applied post-update. Why this causes the problem: The CPU or GPU is prevented from maintaining sustained boost clocks, causing periodic down-clocking that coincides with frame generation.

SECTION 4: SOLUTIONS

Solution 1: Disable Core Isolation Memory Integrity

Difficulty: Medium Time Required: 5 minutes Success Rate: High Prerequisites: Administrator access required, may require system restart. Steps:

Press the Windows key, type "Core Isolation" and select the matching system setting.
Locate the "Memory Integrity" toggle switch. If the switch is ON (or the setting is grayed out and ON), it must be disabled.
If the toggle is accessible, switch it to OFF. If it is grayed out, you must first disable the "Virtual Machine Platform" Windows feature.
To disable Virtual Machine Platform, press Windows key, type "Turn Windows features on or off" and open the control panel. Uncheck the box for "Virtual Machine Platform". Click OK and restart the computer.
After restart, return to the Core Isolation settings. The "Memory Integrity" toggle should now be accessible. Switch it OFF.
The system will prompt for another restart. Perform this restart to complete the configuration change.

Technical Explanation: This resolves the primary conflict between Windows 11 24H2's default security hardening and Fortnite's anti-cheat kernel drivers, removing the virtualization overhead that causes severe performance degradation. Verification: Launch Fortnite and enter a match. The periodic severe FPS drops and audio cutouts should be eliminated. Performance monitoring will show stable GPU utilization.

Solution 2: Perform a Clean GPU Driver Reinstallation with DDU

Difficulty: Advanced Time Required: 15 minutes Success Rate: Medium Prerequisites: Administrator access, internet connection to download drivers. Steps:

Download the latest GPU driver from AMD's official website for the Radeon RX 9070 XT.
Download Display Driver Uninstaller (DDU) from guru3d.com.
Boot Windows into Safe Mode. This is done via Settings > System > Recovery > Advanced startup > Restart now. Then navigate to Troubleshoot > Advanced options > Startup Settings > Restart. Press 4 or F4 to enable Safe Mode.
In Safe Mode, run DDU. Select "AMD" as the device type and click "Clean and restart".
After the system restarts into normal Windows, install the previously downloaded AMD GPU driver package. Select "Factory Reset" or "Clean Install" option during the installation.
After installation, open AMD Adrenalin Software. Navigate to Performance > Tuning. Ensure the GPU tuning profile is set to "Default" or "Gaming".

Technical Explanation: This eliminates corrupted driver files, residual registry entries from previous installations, and incorrect power management profiles that can cause intermittent GPU performance collapse. Verification: The FPS drops should be reduced in frequency and severity. Use a benchmark like 3DMark Time Spy to confirm GPU performance aligns with expected scores for an RX 9070 XT.

Solution 3: Reset Fortnite Game Configuration Files

Difficulty: Easy Time Required: 5 minutes Success Rate: Medium Prerequisites: Fortnite must not be running. Steps:

Press Windows Key + R, type %localappdata% and press Enter. This opens the C:\Users\[YourUsername]\AppData\Local directory.
Navigate to the FortniteGame folder, then the Saved folder.
Locate the Config folder and rename it to Config_OLD.
Locate the WindowsClient folder. Open it and find the GameUserSettings.ini file. Rename this file to GameUserSettings.ini.OLD.
Launch the Epic Games Launcher and start Fortnite. The game will generate fresh, default configuration files.

Technical Explanation: This removes any corrupted or incompatible graphical and performance settings that were carried over from before the December 20th update, forcing the game to use stable defaults. Verification: Upon launching, Fortnite will display video settings at default levels. The severe hitching should be absent, though FPS may be lower until optimal settings are reapplied manually.

Solution 4: Adjust Fortnite Graphics Rendering Mode

Difficulty: Easy Time Required: 3 minutes Success Rate: Medium Prerequisites: Access to Fortnite in-game settings. Steps:

Launch Fortnite and go to the main menu.
Open Settings (gear icon), and navigate to the Video Settings tab.
Locate the "Rendering Mode" setting.
If set to "DirectX 12", change it to "Performance Mode - Alpha". Apply the changes and restart the game when prompted.
If already on Performance Mode, switch to "DirectX 11". Apply and restart.
If the issue persists on the new mode, switch to the other available option (DirectX 12 or Performance).

Technical Explanation: This changes the underlying graphics API and shader compilation method. Performance Mode uses a significantly different renderer that often bypasses driver-level issues present in the DirectX 11 or 12 paths. Verification: The specific pattern of audio cutting out with FPS drops is resolved. Performance should be consistent, though visual fidelity may differ based on the selected mode.

Solution 5: Modify Windows Power & GPU Settings

Difficulty: Medium Time Required: 5 minutes Success Rate: Low Prerequisites: Administrator access for power plan, AMD Adrenalin Software installed. Steps:

Press Windows key, type "Edit power plan" and select it.
Click "Change advanced power settings".
In the new window, expand "Processor power management", then "Minimum processor state". Set it to 100% for both "On battery" and "Plugged in".
Expand "PCI Express", then "Link State Power Management". Set both settings to "Off".
Click Apply and OK.
Open AMD Adrenalin Software. Go to Performance > Tuning. Ensure "GPU Tuning" is enabled and set to "Custom". Manually set the "Min Frequency" to within 100-200 MHz of the "Max Frequency" to prevent large clock swings.

Technical Explanation: This prevents the CPU and PCIe bus from entering low-power states during gameplay, which can cause latency spikes. It also stabilizes GPU clock speeds, eliminating dips due to aggressive power saving. Verification: Monitor GPU-Z or Adrenalin Software metrics during gameplay. The GPU Core Clock should remain stable at high frequencies without significant downward fluctuations.

SECTION 5: PREVENTION

Maintain a system restore point before installing major Windows feature updates or GPU drivers. Configure Windows Update to delay feature updates for 60 days via Settings > Windows Update > Advanced options. Regularly export functional Fortnite configuration files from %localappdata%\FortniteGame\Saved\Config after achieving stable performance for backup. Before updating Fortnite, close all background applications that utilize overlay or injection techniques, such as Discord overlay, MSI Afterburner, or screen recording software. Monitor the Epic Games Launcher news section for known issues following game updates.

SECTION 6: WHEN TO CONTACT SUPPORT

Contact Epic Games Support only after confirming the issue persists across a clean Windows installation and with all third-party applications terminated. Required diagnostic information includes the Fortnite game logs located in C:\Users\[YourUsername]\AppData\Local\FortniteGame\Saved\Logs and a DxDiag report generated by executing dxdiag and saving all information. Provide the exact build version of Windows 11 from winver command. Official support channels are accessible via the Epic Games Help Center at epicgames.com/help.