Deferred Procedure Call (DPC) manages the execution of low-priority tasks related to hardware and device drivers. While its purpose is to defer less time-sensitive operations so that critical tasks get processed first, when high, it can lead to performance issues, particularly in real-time tasks like audio-video streaming or editing. In today’s blog, we will guide you on how to fix high DPC latency on both Windows 11 and 10. Let’s get started.
Reasons for High DPC Latency on Windows 11/10 and How to Fix It
When hardware needs attention or a device driver requires service, it generates an interrupt to alert the CPU. Now Windows OS executes an interrupt service routine (ISR) to respond to them. DPCs defer certain tasks that are related to these interrupts to a later time. High-priority ones are processed before low-priority ones. When one driver takes longer than usual to perform its task, it simultaneously delays the task of other drivers as well, which ultimately can make the PC appear sluggish. In technical terms, this is what we call DPC latency.
Here are some of the common reasons for high DPC latency on Windows:
- Outdated or Faulty Drivers
- Excessive Background Processes
- Overloaded CPU
- Misconfigured System Settings
- Faulty Hardware Components
Quick Answer
Update the graphics and audio drivers on the PC. If that does not help, change the power plan.
1. Launch the Control Panel and select Large icons from the View by drop down menu.
2. Click on Power Options and select High Performance power plan.
Method 1: Switch to New Power Plan
High Performance or Ultimate Performance power plans maximize the processing power of the CPU, which then runs at higher clock speeds consistently. Hence, it can respond more swiftly to handle the Deferred Procedure Calls.
1. Launch the Control Panel, expand the View by dropdown menu in the top right corner, and select Large icons.
2. Click on Power Options and select the High performance or Ultimate performance option.
However, do note that, as this will use more power, it would result in rapid depletion of the battery. If that’s not feasible for you, consider the other methods mentioned below.
Method 2: Update Graphics and Audio Drivers
Graphics and audio drivers handle a significant amount of data and real-time processing. If these drivers are outdated or malfunctioning, they might struggle to keep up with the demands of processing tasks, resulting in high DPC latency. To update these drivers, you can follow our guide on How to Update Graphics Drivers in Windows 11 and How to Update Audio Drivers in Windows 11.
Method 3: Modify Registry
Certain hardware processes can contribute to latency issues. Modifying these settings via the Registry may influence how these processes interact with the system and fix the occurrence of high DPC latency in Windows 11.
Note: Make a backup of registry keys to restore to previous settings in case of manual errors during modification.
1. Press the Win + R keys to open the Run dialog box.
2. Type regedit and click OK. If prompted, select Yes in the UAC prompt.
3. In the Registry Editor, go to the following path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Video\{DEB039CC-B704-4F53-B43E-9DD4432FA2E9}\0000
4. Right-click on the 0000 key, click on New, and then select DWORD (32-bit) Value from the context menu.
If you encounter any errors at this step, you can follow our guide on Fix Cannot create key error writing to the registry.
5. Name the DWORD value key as PerfLevelSrc.
6. Double-click on the PerfLevelSrc key and modify its Value data to 3322.
7. Similarly create three more DWORD values named: PowerMizerEnable, PowerMizerLevel, and PowerMizerLevelAC.
8. Set the Value data for PowerMizerLevel and PowerMizerLevelAC as 1.
9. Click OK to save the changes made to the Registry and Restart your PC.
Method 4: Disable Dynamic Ticking
Dynamic Ticking is a feature in Windows that adjusts the timing of the system clock. System adjustments in clock timing can potentially cause irregularities in the handling of Deferred Procedure Calls. Here’s how to disable it:
1. Run Command Prompt as administrator.
2. Type the following command and press Enter: bcdedit /set disabledynamictick yes
3. Once the command is executed successfully, Restart the PC.
Method 5: Disable IPv6
IPv6 and IPv4 are two different network protocols. Enabling both simultaneously might occasionally lead to conflicts and increased network processing overhead, hence a higher DPC latency. Here’s how to disable IPv6:
1. Press the Windows key + R to open the Run dialog box.
2. Type ncpa.cpl in the text field and press Enter to open the Network Connections window.
3. Right-click on the network connection you’re using (such as Ethernet or Wi-Fi) and choose Properties from the dropdown menu.
4. In the list of items, uncheck Internet Protocol Version 6 (TCP/IPv6), click OK to confirm the changes, and close the properties window.
Method 6: Disable Windows Firewall
Windows Defender continuously performs real-time scanning for malware and other threats. Now the scanning process involves system resources and might occasionally contribute to the discussed issue. By temporarily disabling the firewall the burden on system resources can be reduced and for that, you can follow our guide on How to Disable Windows 11 Firewall.
Method 7: Uninstall Bonjour App (If Applicable)
Bonjour is a networking protocol developed by Apple primarily used for discovering devices and services on a local network. If you’ve connected any Apple device with your Windows PC earlier, you might find this app installed on the system. However, it can run background processes that might cause additional CPU usage and network activity, which can cause higher DPC latency.
1. Open the Control Panel and click on Uninstall a program under Programs.
2. Look for Bonjour in the list of installed programs. Right-click on it and then click Uninstall.
3. Once uninstalled, Restart your computer to ensure the changes take effect.
Method 8: Turn off D0 Packet Coalescing
D0 Packet Coalescing is an energy-saving feature that works by combining smaller packets of data into larger ones before transmitting them. By turning off this feature, you prevent the bundling of data packets, allowing quicker transmission of smaller packets which can fix the high DPC latency issues on Windows 11.
1. Launch the Device Manager and expand the Network Adapters category.
2. Right-click on your network adapter and select Properties from the context menu.
3. Look for properties related to packet coalescing, such as Interrupt Moderation or Packet Coalescing, select it, and choose Disable.
Method 9: Use TCP Optimizer
TCP Optimizer allows users to adjust various network settings to optimize internet connectivity and performance. By fine-tuning these settings, it’s possible to improve network efficiency and reduce potential bottlenecks that could contribute to DPC latency issues.
1. Download TCP Optimizer from the official website and once installed, run it as administrator.
2. Select the Optimal option in the bottom right corner and then click the Apply changes button.
TCP Optimizer will prompt you to Restart your computer to implement the new settings. Save any work and Restart the system.
Method 10: System Restore
If the error persists, the last way is to perform a system restore on the PC, and for that, you can follow our guide on How to Use and Create System Restore in Windows 11.
How Do I Check My DPC Latency?
You can use the DPC latency checker for Windows 11/10 to check whether your PC is facing the discussed issue.
1. Visit the official website of Resplendence’s LatencyMon page and click on the Download button in the top navigation bar.
2. Scroll down and under System Monitoring Tools, select LatencyMon 7.31 (or any latest version) to download it to the PC.
3. Install the downloaded .exe file.
4. Open the LatencyMon app and click on the Start monitor button (green triangular icon) in the top-left corner.
5. Let the monitoring run for several minutes to gather sufficient data and then click on the Stop monitor button (square icon).
6. Go to the Stats tab. Here, you can check all your statistics.
- If the DPC and ISR routines are under 2000µs, your PC can handle real-time audio dropouts.
- If it’s between 2000-4000, it’s not ideal.
- If it exceeds 4000µs, it’s a severe issue.
In general, DPC latency is considered high if it exceeds 2000µs. High DPC latency can mess up your audio on the computer. You might notice problems like video stuttering, inconsistent performance with your mouse or keyboard, or more commonly, audio issues such as dropouts, clicks, and popping sounds.
Is DPC latency better On Windows 10 or 11?
Both Windows 10 and 11 can experience DPC latency issues. Its performance between both versions might vary depending on individual system configurations, hardware, and software.
We hope our guide helped you fix high DPC latency on both Windows 11 and Windows 10. If you have any queries or suggestions for us, feel free to let us know in the comments section. Stay connected to TechCult for more such troubleshooting guides.
