DPC (Deferred Procedure Call) is a mechanism in Windows makes the system execute low-priority tasks later when the system is idle and high-priority tasks first. As important as this arrangement is, it has a problem of latency at times.
Cause
The cause behind high DPC latency is an issue with device drivers. While they need to updated on time to avoid such issues, once you start facing the problem, merely updating it might not be enough.
Try the following solutions sequentially to resolve the issue:
Solution 1] Disable D0 Packet Coalescing
1: Press Windows key + R from the keyboard to open the Run command.
In the Run command search box, type ncpa.cpl and press OK to open the Network connections window.
2 – Now, right click on your network adapter and click Properties
3 – Click Configure
4 – Click on Advanced Tab
5 – Click on D0 Packet Coalescing to select it and then choose disabled.
Solution 2] Change the power plan
The power plan could be the main culprit behind DPC latency, since the balanced power mode confuses the system of which task to prioritize and which not to. The power saver plan will shift the focus to high-priority tasks and the the high performance plan would accelerate all tasks.
1] Press Win + R to open the Run window and type the command powercfg.cpl. Hit Enter to open the Power options window.
2 ] Change the plan to High performance plan.
Solution 3] Update the Display drivers
While updating the drivers would be more of a prevention than a cure, we could try it and check if we are lucky enough to resolve the issue.
1 – Search Device manager in Windows search box.
2 – Now, Click on Device manager to Open device manager
3 – Now, Double click on Display adapters to expand it.
4 – After that, Right click on your display driver and click on Update driver.
5 – Click on Search automatically for drivers.
The driver will be auto updated.
Solution 4] Disable dynamic ticking and update the graphic card’s drivers
As suggested above, DPC latency could be blamed on drivers more than anything, and the main culprit is assumed to be the graphic drivers. The following procedure could help with the same:
1] Press Win + R to open the Run window and type the command cmd. Hit Enter to open Command Prompt.
2] Enter the following command:
bcdedit /set disabledynamictick yes
3] After pressing Enter, wait till the command is executed successfully.
4] Exit Command Prompt
Solution 5] Use TCP Optimizer
1 – Download TCP Optimizer from here
2 -Right click and Choose run as administrator to open it.
2 -Now, Select Optimal settings and click on Apply changes .
Solution 6] Temporarily disable Firewall
The Firewall is another probable reason behind DPC latency. While we cannot do away with iot for security reason, it would be wise to check if it is interfering to isolate the cause. Disable the Firewall temporarily and check if it makes a difference.
Solution 7] Disable Internet Protocol version 6
While someday in future, we might need IPv6, as of present, it interferes with many functions of the system. Disabling it and shifting to IPv4 is a good idea. The procedure is as follows:
1] Press Win + R to open the Run window and type the command ncpa.cpl. Hit Enter to open the Network Connections window.
2] Double-click on your network adapter and the click on Properties.
3] In the following list, uncheck the box next to Internet Protocol version 6.
4] Click on Apply and the OK to save the settings.
Solution 8] Disable the Bonjour application
The Bonjour application by Apple is known to cause the issue in Windows system.
1] Press Win + R to open the Run window and type the command control panel. Press Enter to open the Control Panel.
2] Open Programs and Features from among the option. It would display the list of installed programs.
3] Right-click and uninstall Bonjour.