High ISR and DPC latency while gaming or idle

[npena]

Here's a trace with the script you sent me. I even checked it to be sure there were no lost events. The issue occurs near the end of the trace.

 

[cwsink]

What sort of glitch was it? Audio, video, or both?

 

[npena]

It was both. My audio dropped out entirely for maybe a second twice within 2 seconds, then it occurred after I finished the trace as well.

 

[cwsink]

I'm not seeing anything that suggests ISR or DPC latency would be causing issues in the trace. If you look at the attached screenshot you'll see the DPC Duration by CPU and ISR Duration by CPU graphs with the Duration (Fragmented) max column sorted from highest to lowest. On core 0 the maximum DPC fragment ran for 0.190500 milliseconds and the maximum ISR fragment ran for 0.177700 milliseconds. So the length of time that an ISR or DPC ran should not have been long enough to cause any noticeable audio or video glitches. Those ISR and DPC duration values are actually very good on all of the cores, really.

I notice you're using Windows 10 19H1 (18362). I remember people complaining about "stuttering and hitching" on some systems which seemed to come down to memory management performance issues. Windows was trying to free up standby memory but doing so seemed to cause noticeable stuttering - particularly in games. I don't remember exactly which versions of Windows 10 was available when that issue started but it seems like those complaints have tapered off since 19H2 and 2004. Have you already tried newer versions of Windows 10 to know if they also have the same problem on your system?

 

[npena]

My computer should be updated to the most recent version of windows. If it isn't, it doesn't give me an option to update it in any of the system settings. Where could I go about updating from 19H1 to 19H2?

 

[cwsink]

Settings -> Update & Security -> Windows Update then click Check for updates button; should show any available updates.

 

[npena]

I've just updated my system to the newest version, I'll see how things are during use and see if my performance issues have subsided.

 

[npena]

It seems that the update did not fix the issue, I'm still having the same audio and visual issues.

 

[cwsink]

There is a tool called Media eXperience Analyzer (MXA) from Microsoft that is specifically for trying to find audio/video glitches in media playback. It would need to be installed on your computer and then you'd use the GUI version of Windows Performance Analyzer (WPA) to first import a performance profile that comes with MXA and then run a WPA trace with that profile enabled in WPA. However, there doesn't seem to be a way to save the trace to memory during the trace when using that profile - only to a file - which could generate traces with lost events like before. Also, the trace grows very large very quickly with that profile so if the problem isn't able to be reproduced in a short amount of time the file will likely be unusable.

Do the glitches happen randomly and only once with a long gap between glitches or does the system keep glitching constantly in rapid succession after the initial glitch?

 

[npena]

The glitches seem to happen with relatively long gaps between occurrences, usually twice in a row with audio drop outs specifically in the game and not in other programs, and my framerate dropping to the teens then rising back up to regular numbers.

 

[cwsink]

I'm going to need to review some information to see if I can give you a script that will hopefully be able to capture what is happening. It won't be until tomorrow or the next day but I'll get back to you as soon as possible.

 

[npena]

That's absolutely fine, thank you for your help and I'll be sure to check for your response when you have a script.

 

[cwsink]

If the glitches aren't being caused by ISR/DPC latency then it might be that whatever core/thread that is responsible for playing audio is getting stuck waiting on something so let's try a script that also captures context switches. It works the same way from a user point of view but to make it a little easier to identify where the glitch is happening please count to 10 after a glitch and then end the trace. That should separate the glitch from possible CPU usage spikes caused by ending the trace.