Performance Issue Fortnite

Fortnite DX12 Slow FPS Rise on Startup - Shader Cache Fix Guide

📅 Published: 2026-02-05 🔄 Updated: 2026-02-05 👥 Reports: 2 ⚡ Severity: 🟢 Low

🎯 Quick Answer

Set the Shader Cache Size to 10 GB in NVIDIA Control Panel and disable Windows Controlled GPU Scheduling to resolve the slow FPS ramp-up in DirectX 12.

SECTION 1: OVERVIEW

This error is defined by a gradual performance degradation and recovery cycle specific to the DirectX 12 rendering API in Fortnite. The system exhibits a significant, temporary reduction in frames per second (FPS) upon application launch or after significant scene changes, with performance normalizing after approximately 60-90 seconds of continuous operation. The issue occurs exclusively on the Windows platform when using the DirectX 12 backend. It is most prevalent in game versions following the implementation of more aggressive runtime shader compilation. This is a common performance anomaly with moderate severity, primarily impacting initial gameplay and menu navigation rather than causing crashes. No formal error codes are generated; the malfunction is purely behavioral and measurable through frame-time analysis.

SECTION 2: SYMPTOMS

The application launches with a locked or severely reduced frame rate, typically between 30-60 FPS, regardless of system hardware capabilities. Frame timing exhibits consistent stuttering during this period. Performance metrics show a steady, linear increase in FPS over 60-90 seconds until reaching the system's expected stable frame rate. A secondary symptom manifests as transient but severe frame drops when navigating between major UI elements, such as switching from the lobby to the Item Shop or Battle Pass menu. The DirectX 12 renderer is confirmed active. The DirectX 11 renderer does not exhibit this behavior but may yield lower overall performance at peak.

SECTION 3: COMMON CAUSES

Category: Configuration Error Specific technical explanation: An insufficient or disabled Shader Cache size in the GPU driver control panel. When set to "Off" or a low value (e.g., 100 MB), the driver cannot store compiled shaders persistently. This forces a full re-compilation of shader pipelines each session. Why this causes the problem: DirectX 12 utilizes a more explicit, low-level shader model. Without a sufficient cache, the GPU driver must compile thousands of shaders at runtime, causing CPU-bound stalls and low FPS until compilation completes. Category: Software Conflict Specific technical explanation: The "Hardware-accelerated GPU scheduling" Windows setting interfering with the DirectX 12 driver's memory management and shader compilation scheduling. Why this causes the problem: This Windows feature takes control of GPU memory management from the individual application/driver. This can introduce overhead and suboptimal scheduling during the intensive, asynchronous shader compilation processes used by Fortnite's DX12 renderer. Category: Game Bug Specific technical explanation: Corrupted or invalidated local shader cache files within the Fortnite user directory, despite correct driver-level settings. Why this causes the problem: The game maintains its own cache of compiled shader data. If this data is malformed, the game ignores it and falls back to runtime compilation, but may not efficiently repopulate the cache. Category: Configuration Error Specific technical explanation: The in-game "Rendering Mode" is set to "DirectX 12" while the "Use Performance Mode" setting for individual cosmetics is disabled, maximizing shader complexity. Why this causes the problem: This combination ensures the highest possible shader count and variety must be compiled. Without aggressive pre-compilation and caching, this exacerbates the initial compilation period. Category: Hardware Issue Specific technical explanation: The game is installed on a traditional Hard Disk Drive (HDD) or a slow Solid State Drive (SSD). Why this causes the problem: Shader cache files are read from and written to disk continuously during compilation. Slow storage I/O creates a bottleneck, prolonging the time required to load cached shaders and save new ones. Category: Software Conflict Specific technical explanation: Outdated or corrupted Microsoft DirectX 12 runtime components or Visual C++ redistributables. Why this causes the problem: Fortnite's shader compiler relies on these underlying Windows components. Incompatible or damaged files cause compilation processes to run inefficiently or repeat unnecessarily.

SECTION 4: SOLUTIONS

Solution 1: Configure NVIDIA/AMD Shader Cache Settings

Difficulty: Easy Time Required: 5 minutes Success Rate: High Prerequisites: NVIDIA or AMD graphics driver installed. Steps:

Right-click on the Windows desktop and select NVIDIA Control Panel or AMD Radeon Software.
Navigate to Manage 3D Settings (NVIDIA) or Graphics (AMD) in the left-hand menu.
In the Global Settings tab, locate the Shader Cache Size setting (NVIDIA) or Shader Cache setting (AMD).
For NVIDIA, set this option to 10 GB (or maximum available). For AMD, set it to AMD Optimized or On.
Click Apply.
Launch Fortnite, select DirectX 12, and observe the startup FPS behavior.

Technical Explanation: This allocates sufficient disk space for the GPU driver to persistently store all compiled shaders. On subsequent launches, the driver loads pre-compiled shaders from this cache, eliminating the runtime compilation workload that causes low initial FPS. Verification: Monitor FPS immediately upon reaching the lobby. The frame rate should now be within 10-15% of its stable maximum within 10-15 seconds, not 60-90 seconds. Menu transitions will show minimal stutter.

Solution 2: Disable Hardware-Accelerated GPU Scheduling

Difficulty: Easy Time Required: 3 minutes Success Rate: Medium Prerequisites: Windows 10 version 2004 or later, or Windows 11. Steps:

Press Windows Key + I to open Windows Settings.
Navigate to System > Display > Graphics (Windows 10: Graphics settings).
Click Change default graphics settings.
Locate the setting for Hardware-accelerated GPU scheduling.
Toggle the switch to Off.
Click Yes when prompted to restart your system.
After reboot, test Fortnite's startup performance in DirectX 12 mode.

Technical Explanation: This returns full control over GPU memory management and scheduling to the NVIDIA/AMD driver. The driver's native scheduler is more finely tuned for the rapid, asynchronous shader compilation tasks required by DirectX 12 applications like Fortnite. Verification: The performance ramp-up time is reduced. Use the Windows Game Bar (Win + G) performance widget to confirm GPU scheduling overhead is minimized during the initial launch phase.

Solution 3: Manually Clear Fortnite's Local Shader Cache

Difficulty: Medium Time Required: 10 minutes Success Rate: Medium Prerequisites: Fortnite must be fully closed, including the Epic Games Launcher. Steps:

Press Windows Key + R, type %localappdata%, and press Enter.
Navigate to the FortniteGame folder, then Saved.
Locate and open the DerivedDataCache folder.
Select all files and folders within this directory and delete them.
Navigate back to the Saved folder and open the ShaderCache folder.
Select all files and folders within this directory and delete them.
Empty the Recycle Bin.
Relaunch the Epic Games Launcher and Fortnite. The game will rebuild these caches from scratch during the first launch.

Technical Explanation: Corrupted cache files force the game to recompile shaders but may not be efficiently overwritten. A manual deletion ensures a clean state. The subsequent rebuild creates a fresh, valid cache optimized for the current game and driver version. Verification: The first launch after deletion will be slow as caches rebuild. The second and subsequent launches will demonstrate significantly faster FPS stabilization. Monitor the folder size; it should grow steadily during the first match.

Solution 4: Enable Performance Mode for Cosmetic Items

Difficulty: Easy Time Required: 2 minutes Success Rate: Low-Medium Prerequisites: None. Steps:

Launch Fortnite and enter the main lobby.
Open the Settings menu (top-right icon or Esc key).
Navigate to the Graphics settings tab.
Scroll down to the Advanced Graphics section.
Locate the setting Use Performance Mode.
Set this option to Performance.
Apply the settings and restart the game for the change to take full effect.

Technical Explanation: This setting reduces the visual complexity and unique shader count for equipped cosmetic items. A lower total number of unique shaders reduces the volume of data that must be compiled and cached at runtime, shortening the initial compilation period. Verification: The startup FPS ramp-up time is moderately reduced. This is most effective when combined with a sufficient driver-level shader cache size (Solution 1).

Solution 5: Verify and Repair Microsoft Visual C++ Redistributables

Difficulty: Advanced Time Required: 15 minutes Success Rate: Medium Prerequisites: Administrator access required. Steps:

Press Windows Key + R, type appwiz.cpl, and press Enter to open Programs and Features.
In the list, locate all instances of Microsoft Visual C++ 20XX Redistributable.
Note the years present (2015-2022, 2013, etc.).
Download the latest Visual C++ Redistributable packages from the official Microsoft website. Specifically, obtain both the x64 and x86 versions of the latest release (e.g., 2015-2022).
Run each installer and select Repair. If repair is not an option, select Uninstall, restart your PC, then reinstall the package.
After all repairs/reinstalls are complete, restart your system and test Fortnite.

Technical Explanation: Fortnite's shader compiler and the DirectX 12 runtime rely on these specific libraries. Corrupted or missing files within these packages can cause the shader compilation process to execute redundant operations or fail silently, falling back to slower compilation paths. Verification: System stability is improved. Use a tool like dxdiag (run from Start Menu) to confirm no errors are reported in the DirectX Diagnostic Tool under the "Display" tab.

Solution 6: Migrate Fortnite Installation to an SSD

Difficulty: Advanced Time Required: 30-60 minutes Success Rate: High Prerequisites: A Solid State Drive with sufficient free space, Epic Games Launcher installed. Steps:

Open the Epic Games Launcher.
Click your profile icon in the bottom left and select Settings.
Scroll down to the MANAGE GAMES section.
Locate Fortnite and note the current Install Location.
Click the folder icon to add a new install location on your target SSD (e.g., D:\EpicGames).
Select Fortnite and click Move.
Choose the new SSD location from the dropdown and confirm the move. The launcher will transfer the files.
After completion, launch the game from the launcher.

Technical Explanation: Shader cache operations involve reading/writing thousands of small files. An SSD provides orders of magnitude faster random read/write speeds compared to an HDD, drastically reducing the I/O bottleneck during the initial cache loading and population phase. Verification: The duration of the initial low-FPS period is substantially shortened. General game loading times from launch to lobby are also significantly improved.

SECTION 5: PREVENTION

Maintain a minimum 10 GB allocation for the GPU driver Shader Cache setting. After every major graphics driver update (e.g., moving from NVIDIA 5xx to 6xx series), perform a clean driver installation using the "Custom" option and select "Perform a clean installation." Periodically verify the integrity of Fortnite's game files through the Epic Games Launcher's "Verify" function. Avoid manually deleting files in the DerivedDataCache and ShaderCache folders after the initial fix unless a new, persistent performance issue arises. Schedule a monthly review of Windows optional updates, which can contain critical DirectX runtime updates.

SECTION 6: WHEN TO CONTACT SUPPORT

Contact Epic Games Support if all documented solutions fail and the issue persists exclusively in DirectX 12 mode while DirectX 11 functions normally. Provide the full diagnostic report generated by the Epic Games Launcher (Settings > Fortnite > Troubleshoot > Create Diagnostic Report). Include the specific model of your GPU and the exact driver version. Also provide the dxdiag.txt report (run dxdiag and select "Save All Information"). Official support channels are accessible via the Epic Games Help Center website. Do not submit reports based on forum speculation.