Performance Issue
Fortnite
Fortnite PC Micro-Stuttering and FPS Drops Fix Guide
🎯 Quick Answer
Disable NVIDIA Reflex Low Latency in Fortnite's Video settings and set Shader Cache Size to Unlimited in the NVIDIA Control Panel to resolve micro-stuttering caused by driver-level frame pacing issues.
SECTION 1: OVERVIEW
The error is defined as intermittent micro-stuttering, characterized by severe, sub-second frame rate drops to single-digit FPS within an otherwise high-frame-rate environment. This issue manifests exclusively on the Windows PC platform across all Fortnite game modes, including Battle Royale and Creative. The problem occurs in the current production build of Fortnite (Chapter 5, Season 3) and has been documented in several preceding versions. This is a common performance anomaly reported on high-specification systems. The severity is classified as game-breaking for competitive play, as the momentary freeze disrupts aiming precision and input response during critical engagements. No specific error codes are generated; the failure is purely a performance degradation event within the rendering pipeline.SECTION 2: SYMPTOMS
The primary symptom is a periodic, severe drop in frames per second (FPS) from a stable 200-500 FPS to a value between 1-9 FPS. This drop persists for a duration of 16-67 milliseconds, correlating to 1-4 missed frames at a high refresh rate. The event presents as a visible hitch or freeze in gameplay animation. Input registration may be delayed during the event. The stutter occurs at semi-regular intervals, often every few seconds, during active gameplay across all maps and modes. The system maintains high average FPS metrics, but the frame time graph exhibits pronounced, sporadic spikes. No crash to desktop, error message, or application termination occurs.SECTION 3: COMMON CAUSES
- Category: Configuration Error - NVIDIA Reflex Setting Conflict. The "NVIDIA Reflex Low Latency" setting set to "On + Boost" can cause driver-level scheduling conflicts with Fortnite's internal frame pacing on RTX 5000 series GPUs, inducing periodic stalls in the render queue.
- Category: Software Conflict - Shader Cache Invalidation. The NVIDIA Shader Cache size is insufficient or becomes corrupted, forcing real-time shader compilation during new scene loads, which halts the rendering thread and causes a frame-time spike.
- Category: Game Bug - Unreal Engine 5 Nanite/Lumen Threading Issue. A known bug in specific Unreal Engine 5 builds causes temporary blocking between the geometry processing (Nanite) and lighting (Lumen) threads, resulting in a main thread stall.
- Category: Configuration Error - Full-Screen Optimization / Game Bar Interference. Windows 10/11 "Full-Screen Optimizations" and the Xbox Game Bar overlay inject hooks into the DirectX 12 swap chain, which can cause timing variances and brief presentation delays.
- Category: Hardware Issue - XMP/EXPO Memory Profile Instability. The system's DDR5 memory, while stable in other applications, may have subtiming issues at its rated XMP/EXPO profile that are exposed under Fortnite's specific memory access patterns, causing correctable errors that stall the CPU.
- Category: Software Conflict - Overlay Application Interference. Discord, Overwolf, MSI Afterburner/RivaTuner Statistics Server (RTSS), or NVIDIA GeForce Experience overlays hook into the Direct3D API, and their periodic updates can conflict with Fortnite's anti-cheat (Easy Anti-Cheat), causing a brief suspension of the render thread.
- Category: Configuration Error - Power Profile/CPU Scheduling. The Windows power plan or AMD Ryzen power profile is set to a balanced or power-saving mode, allowing the CPU cores to rapidly shift states and causing a delay in the primary game thread's scheduling.
SECTION 4: SOLUTIONS
Solution 1: Adjust Critical Graphics & Driver Settings
Difficulty: Easy Time Required: 5 minutes Success Rate: High Prerequisites: None Steps:- Launch Fortnite and navigate to the Settings menu.
- Select the Video Settings tab.
- Locate the NVIDIA Reflex Low Latency option. Change its setting from "On + Boost" to "On" or "Off". Apply the changes.
- Exit Fortnite completely.
- Right-click the Windows desktop and open NVIDIA Control Panel.
- Navigate to Manage 3D Settings > Global Settings tab.
- Find the "Shader Cache Size" setting. Set it to "Unlimited".
- Click Apply. Restart your computer.
Solution 2: Perform a Clean GPU Driver Installation
Difficulty: Medium Time Required: 10 minutes Success Rate: Medium Prerequisites: Administrator access Steps:- Download the latest NVIDIA Game Ready Driver from the official NVIDIA website.
- Download the display driver uninstaller utility, DDU, from www.wagnardsoft.com.
- Boot Windows into Safe Mode. (Open System Configuration > Boot tab > check "Safe boot" > Network).
- Run DDU. Select "NVIDIA" from the device type dropdown and click "Clean and restart".
- After the restart into normal Windows, install the previously downloaded NVIDIA driver. Select "Custom (Advanced)" installation.
- Check the box for "Perform a clean installation". Complete the installation and restart.
Solution 3: Disable Windows Gaming Interference Features
Difficulty: Easy Time Required: 3 minutes Success Rate: Medium Prerequisites: None Steps:- Locate the Fortnite executable. The default path is
C:\Program Files\Epic Games\Fortnite\FortniteGame\Binaries\Win64\FortniteClient-Win64-Shipping.exe. - Right-click the executable, select Properties, and navigate to the Compatibility tab.
- Check the box for "Disable full-screen optimizations".
- Click "Change high DPI settings". At the bottom, check "Override high DPI scaling behavior" and select "Application" from the dropdown.
- Press Windows Key + G to open the Xbox Game Bar. Go to Settings (cog icon) and ensure "Record game clips, screenshots..." is toggled OFF.
- In Windows Settings > Gaming > Game Bar, turn off "Remember this is a game".
Solution 4: Configure Fortnite for Maximum Performance
Difficulty: Medium Time Required: 7 minutes Success Rate: Medium Prerequisites: None Steps:- In Fortnite Video Settings, set Rendering Mode to "DirectX 12" (requires restart). This provides more stable frame pacing than DX11 or Performance Mode on high-end systems.
- Set View Distance to "Epic". Paradoxically, lower settings can shift load to CPU; Epic ensures the GPU is fully utilized.
- Set Textures, Effects, and Post Processing to "High".
- Set Shadows, Global Illumination, Reflections, and Ray Tracing to "Off".
- Ensure VSync and Motion Blur are Off. Set Frame Rate Limit to "Unlimited".
- Open Windows Settings > System > Power & battery > Power mode. Set to "Best performance".
- For AMD Ryzen systems, install the latest AMD Chipset Drivers from AMD.com. Afterwards, in Windows Power Options, select the "AMD Ryzen High Performance" plan.
Solution 5: Eliminate Third-Party Overlay Conflicts
Difficulty: Easy Time Required: 4 minutes Success Rate: High Prerequisites: None Steps:- Completely close Discord, Overwolf, and any other chat or streaming applications.
- Exit MSI Afterburner and RivaTuner Statistics Server (RTSS) from the system tray.
- Open the NVIDIA GeForce Experience application. Click the Settings (gear icon).
- Under the "General" tab, toggle "In-Game Overlay" to the OFF position.
- Launch Fortnite. Play a full match in a public Battle Royale mode (not creative) to test.
Solution 6: Test Memory Stability and Modify Engine.ini
Difficulty: Advanced Time Required: 15 minutes Success Rate: Low Prerequisites: File editing Steps:- Temporarily enter your system BIOS/UEFI and disable the XMP/EXPO profile for your RAM, running it at its base JEDEC speed (e.g., 4800MHz for DDR5). Test Fortnite.
- If stable, re-enable XMP/EXPO and test with a memory stress tool like TestMem5 with the
anta777extreme profile for 30 minutes to rule out subtle instability. - Navigate to
C:\Users\[YourUsername]\AppData\Local\FortniteGame\Saved\Config\WindowsClient. - Open the Engine.ini file in Notepad. If it doesn't exist, create it.
- Add the following lines at the end of the file:
`
[SystemSettings]
r.OneFrameThreadLag=0
r.GTSyncType=0
r.D3D12.GpuTimeOut=0
r.TextureStreaming=0
`
- Save the file. Right-click the file, select Properties, and check "Read-only" to prevent Fortnite from overwriting it.
SECTION 5: PREVENTION
Maintain system stability by updating the NVIDIA GPU driver only when a new Game Ready Driver specifies Fortnite optimizations. Use DDU for every other driver update. Keep the Fortnite shader cache cleared by periodically deleting the contents ofC:\Users\[YourUsername]\AppData\Local\NVIDIA\DXCache and GLCache after a driver update. Monitor system temperatures using HWiNFO64 to ensure no thermal throttling occurs. Configure a static page file of 16384 MB on your fastest SSD. Avoid modifying the GameUserSettings.ini file for performance tweaks beyond the in-game menu, as Epic Games frequently resets and optimizes this file.
SECTION 6: WHEN TO CONTACT SUPPORT
Contact Epic Games Support if all solutions fail and the issue persists exclusively in Fortnite. Before contacting, gather the following diagnostic data: the full system specification list, a DXDiag report (rundxdiag and save all information), and the Fortnite game logs located in `C:\Users