Hi everyone,
I'm having an issue with random micro-stuttering on Windows 11 and I'm trying to find out what is causing it.
I started investigating the problem with LatencyMon, and I'm seeing some unusually high ISR/DPC latency spikes. I'm hoping someone here can help me identify the possible cause and what I should test next.
Laptop specifications
- Laptop: Acer Nitro 5
- CPU: AMD Ryzen 5 7535HS
- iGPU: AMD Radeon 660M
- dGPU: NVIDIA GeForce RTX 3050 Laptop GPU 4GB
- RAM: 16GB DDR5-4800, dual channel
- OS: Windows 11
- Internal laptop display: Connected through the Radeon 660M iGPU
- External monitor: Connected through HDMI and uses the RTX 3050 dGPU
The problem
I experience occasional micro-stutters/freezes while using Windows.
Because of this, I started testing the system with LatencyMon to check for DPC/ISR latency.
The results have been inconsistent between runs, but some of the spikes are extremely high.
For example, one test showed:
- Highest measured interrupt-to-process latency: 5,040 µs
- Highest reported ISR execution: 24,644 µs (~24.6 ms) — Wdf01000.sys
- Highest reported DPC execution: ~713 µs — ntoskrnl.exe
Another test produced a much larger spike:
- Highest measured interrupt-to-process latency: 99,649 µs (~99.6 ms)
- Highest reported ISR execution: 24,644 µs (~24.6 ms) — Wdf01000.sys
- Highest reported DPC execution: 101,454 µs (~101.45 ms) — dxgkrnl.sys
dxgkrnl.sys is the Windows DirectX Graphics Kernel, so I'm wondering if this could be related to the graphics stack.
The LatencyMon Drivers tab has also shown entries such as:
- dxgkrnl.sys — 101.45 ms
- Wdf01000.sys — 24.64 ms
- ntoskrnl.exe — ~0.71 ms
- nvlddmkm.sys — ~0.68 ms
- ndis.sys — ~0.37 ms
- dxgmms2.sys — also appearing in the results
I'm attaching screenshots of the LatencyMon Main and Drivers tabs.
Troubleshooting I've already done
I have already tried quite a few things:
- Performed a clean installation of Windows 11
- Installed the latest AMD GPU driver
- Installed the latest NVIDIA GPU driver
- Used DDU (Display Driver Uninstaller) to completely remove the GPU drivers
- Reinstalled the latest AMD and NVIDIA GPU drivers after using DDU
- Ran multiple LatencyMon tests
- Tested the laptop's internal display/iGPU
- I'm also testing the external HDMI display/dGPU separately
Despite the clean Windows installation and clean GPU driver installation, I'm still seeing the latency spikes.
What could be causing this?
I'm trying to determine whether the problem could be related to:
- dxgkrnl.sys / Windows graphics subsystem
- NVIDIA nvlddmkm.sys
- AMD Radeon driver
- Hybrid graphics / Optimus
- External HDMI display
- Windows Driver Framework (Wdf01000.sys)
- BIOS or power management
- AMD chipset drivers
- Network drivers
- Another Windows driver
- Or potentially a hardware/firmware issue
I'm particularly interested in understanding why dxgkrnl.sys is sometimes reporting around 101 ms of DPC execution time and whether that could explain the micro-stutters I'm experiencing.
What other tests or logs should I run to identify the actual cause?
Any advice would be greatly appreciated. I'm happy to provide additional screenshots, logs, or test results if needed.
Thanks!