Title: RTX 4090 + LG 240Hz Ultrawide – Stuttering at All Refresh Rates – Fully Diagnosed, Still Unresolved

Understanding and Diagnosing Microstuttering in High-Performance Gaming Setups: An In-Depth Case Study

In the realm of high-end PC gaming, enthusiasts often seek the best performance and visual fidelity. However, even with top-tier components, technical issues such as microstuttering can persist, disrupting the intended smooth experience. This article examines a recent real-world scenario involving a high-specification gaming PC, detailing the diagnostic process undertaken to identify the root cause of persistent stuttering across various settings and configurations.

System Configuration Overview

Processor: AMD Ryzen 9 7950X3D
Graphics Card: NVIDIA RTX 4090 (PCIe 4.0 x16 confirmed)
Monitor: LG UltraGear 45GS95QE-B (3440×1440 resolution, 240Hz OLED, DisplayPort 1.4)
Memory: 64GB DDR5 RAM with EXPO profile enabled, validated through memory testing tools
Operating System: Windows 11, version 22H2, freshly installed to ensure a clean environment
Motherboard BIOS: Updated to the latest F36 version
Issues Encountered

Despite utilizing high-end hardware, the user experienced microstuttering across multiple games, including League of Legends, Apex Legends, and Counter-Strike 2. Notably, this stuttering persisted at various refresh rates—240Hz, 220Hz, 200Hz, and even down to 144Hz—and was evident even when frame rates were capped and a stable refresh rate was set. The problem was not limited to gameplay; desktop interactions, such as taking screenshots, also triggered noticeable freezes and GPU clock spikes.

Diagnostic Tools and Testing Procedures

To systematically identify potential causes, the user employed an array of diagnostic approaches:

• Latency Analysis: LatencyMon revealed DPC (Deferred Procedure Call) spikes associated with driver components such as nvlddmkm.sys (NVIDIA display driver) and wdf01000.sys (Windows Driver Framework). Notably, these spikes occurred even during idle periods, suggesting background driver activity affecting system latency.
• Frame Timing Verification: PresentMon logs confirmed irregular frame pacing, indicating inconsistent frame delivery that could cause visual stutter.
• System Stress Testing: Running OCCT stress tests for CPU and GPU confirmed thermal and power stability, ruling out hardware overheating or undervoltage issues.
• Component and Software Checks: Multiple clean installations of Windows 11, BIOS updates, driver reinstallation with various versions (both Studio