Well, this is a tiny but important knowledge and I just noticed it today.
First of all, you need to know one thing: if DPC Latency is higher than 1000 μs, it will cause some strange phenomena such as sound lagging, and the video games have low performance.
How to detect
Go to https://www.resplendence.com/latencymon to download the latencymon software. It’s very professional, easy to use, and home-free.
Then open it, click the start button (a green triangle icon), and the software will record the highest DPC latency automatically in the background.
Now we need to run a heavy load program. Here I recommend using video games, online games are better.
Play the games for a while and switch back to the latencymon window, to see if the DPC value is over 1000 μs. If you find it is over 1000 μs, it means that your system has a latency problem.
How to solve (for Nvidia GPUs)
The latencymon will tell you what file caused the latency problem. If you see the file is related to the Nvidia driver (e.g. nvlddmkm.sys), here is a very easy solution.
Open the Start Menu or Windows Search, input the keywords “choose a power plan” and get into it. Then you just need to switch the Balanced plan to High performance.
If you are using the AMD Ryzen CPU, there should be the other power plan called “AMD Ryzen Balanced”. In fact, this plan is as bad as the default balanced plan as to the high DPC latency. You should choose the default high performance plan or the AMD Ryzen High performance plan.
To test the effect, go to latencymon first and click the stop button (a red rectangle icon), then click the start button again. It will reset the records. Restart your video game and play for a while, you will see the value is no higher than 1000 μs anymore.
To get the optimal experience, please restart your PC right now.
How to solve (for other problems)
If you find the problem caused file is related to others, please consider the following methods:
- Update your BIOS
- Check your RAMs, especially the overclocking profile. Try to use the default frequency and parameters
- Update your system drivers, especially the chipset driver and the GPU driver
- Update your Windows system via Windows Update
- Use “sfc /scannow” command to repair the system files
- Consider using anti-virus software
- Reinstall your system
Further details
Look at the top bar of latencymon. The Main tab is the default. It only shows the highest record. But what if we want to find the chance of happening? Just click the stop button (a red rectangle icon) and then switch to the Stats tab. Here you can see the report of this time’s monitor. A screenshot to save the report is recommended.
Look at the reports above. We can see that even though both plans have once a high DPC latency, the data shows that the high performance plan is better.
If you don’t care about the difference, you can choose the balanced plan as you wish.
Jaylin Wu 