High DPC Latency Issues in Online Games - ntoskrnl.exe, nvlddmkm.sys, dxgkrnl.sys, Wdf01000.sys, HDAudBus.sys

Question

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Hello Microsoft Support Team,

I am experiencing severe FPS drops and system stutters, particularly in online games (e.g., Apex Legends, World of Tanks, Battlefield). Offline games like Red Dead Redemption 2 and Elden Ring run perfectly fine without any issues.

To diagnose the problem, I used LatencyMon. The program consistently reports high DPC latency values, indicating a problem with several drivers. After analyzing the results, the following drivers appear to be the primary cause of the high DPC latency:

• ntoskrnl.exe: High DPC count (e.g., 16809)
• nvlddmkm.sys: High DPC count (e.g., 11622)
• dxgkrnl.sys: High DPC count (e.g., 6015)
• Wdf01000.sys: High DPC count (e.g., 1887)
• HDAudBus.sys: High DPC count (e.g., 1184)

I have already performed several troubleshooting steps to resolve this issue, but the problem persists. The steps I have taken include:

• BIOS Update: I updated my motherboard's BIOS to the latest version, which resolved the system freezing issue but did not eliminate the high DPC latency.
• GPU Driver Clean Installation: I used DDU (Display Driver Uninstaller) to completely remove the NVIDIA drivers in Safe Mode and then performed a clean installation of the latest drivers from the NVIDIA website.
• Audio Driver Update: I uninstalled my audio drivers and performed a clean installation of the latest audio drivers from my motherboard manufacturer's website.
• Chipset Driver Update: I installed the latest chipset drivers from my motherboard manufacturer's website.
• Windows Power Plan Settings: I have set my power plan to "High Performance" and disabled "PCI Express Link State Power Management" in the advanced settings.

Despite these efforts, LatencyMon still reports high DPC latency, and I continue to experience stuttering in online games. The issue seems to be complex, potentially involving a driver conflict or an underlying hardware-software compatibility problem.

Could you please provide further assistance and guidance on how to resolve this issue?

Thank you for your time and help.

Best regards,

Kaan

Answer 1

Willl be great to know what you test and what happened in each case, specially in network tests as I’m seeing two key details from these screenshots:

1. portcls.sys on CPU 11 has a huge DPC execution spike (42 ms)
   • This is the Port Class driver, part of Windows’ audio subsystem, large spikes here often come from audio drivers, USB headsets, or HDMI audio from the GPU.
2. tcpip.sys shows up on multiple CPUs as the top ISR/DPC executor
   • This is your network stack driver, which explains why the stutters mainly hit online games and not offline ones, points to network adapter driver inefficiency, packet handling delays, or something intercepting packets (security software, overlay, VPN).

Your stutters are likely the result of network latency spikes + audio driver latency stacking together. The GPU (nvlddmkm.sys / dxgkrnl.sys) is also involved, but those are often secondary effects when network or audio causes a delay chain. you could try this:

1. In Device Manager > Network Adapters, right-click > Uninstall device (you already trie to update, but this will be a reinstallation), check if Delete the driver software for this device if available.

Reboot, then install the latest driver directly from your motherboard or NIC manufacturer, not from Windows Update.

1. In your network adapter Advanced properties:
   • Disable Interrupt Moderation
   • Disable Energy-Efficient Ethernet
   • Set Speed & Duplex to a fixed value like 1.0 Gbps

Also:

1. Temporarily disable your onboard audio in Device Manager.
2. If you use HDMI/DisplayPort audio via NVIDIA, also disable NVIDIA HD Audio device.
3. Test if portcls.sys spikes vanish, reinstall the latest audio drivers from your motherboard vendor.

Again, will be great to know the results on each test, if you carry all or you couldn´t.

Answer 2

Hi! Since you’ve already done BIOS, chipset, GPU, audio updates, DDU cleaning, and high-performance power plan, the remaining possible causes fall into three main categories:

• Network-related drivers
• Background software
• Advanced driver tweaks.

Online, only stuttering with smooth offline play often points to network stack latency.

• Update your LAN/Wi-Fi drivers directly from your motherboard/chipset vendor, not just Windows Update.
• If you use Wi-Fi, try wired Ethernet temporarily, this will rule out wireless driver spikes.
• Try a different network to discard troubles with it.

A clean boot is one of the fastest ways to confirm if your high DPC latency is being caused by third-party software or drivers loading at startup.

1. Press Win + R, type: msconfig
2. Go to the Services tab.
3. Check Hide all Microsoft services (prevents disabling core Windows components).
4. Click Disable all.
5. Then go to the Startup tab > click Open Task Manager.
6. Disable all startup items.

Reboot the System.

1. Test Your Games and check the results.