I think I've found an issue with DPC latency on Windows 11 with 12 and 13 gen Intel processors

Hardware CPU
1

Hi, though I have been an occasional viewer of
the YouTube channel, this is apparently not my first time posting to this forum, but I don’t remember being here before at all lol. Hopefully I put this in the right category. To be honest I am not knowledgeable about anything I’m about to talk about, so please forgive the fact that I am way out of my depth here.

I recently put together a system for music production. It’s not the fastest machine I could have built, but coming from an old i7 2600k build, its quite the change.

Specs:
-13600kf
-Gigabyte UD AC motherboard
-Corsair Vengeance DDR5 @5600Mhz
-WD Sn770 SSD
-Evga Gtx 1070
-Crucial 1tb SATA SSD
-Samsung 1tb 870 Evo SATA SSD
-Seasonic Focus+ 750w PSU

A while after setting up Windows 11, found that my DAW (studio one) was reporting spikes in cpu usage. But if I checked HWMonitor usage would be really low, around .5% overall.

Someone on Reddit told me to check out the program latencymon. So I did, and found I was getting massive “interrupt to process latency” spikes. After trowling various forums and troubleshooting for 2 days, trying just about everything, I found that this only seems to be a problem on Windows 11. While my “highest interrupt to process latency” result in W11 was in the thousands, the result in W10 is in the low hundreds.

I then did some searches on the internet, looking for posts on Reddit and different forums. Turns out there are a fair number of posts from people experiencing the same latency spikes on 12 or 13 gen Intel and Windows 11. Posted a thread on the Intel subreddit for people to post their LatencyMon results, didn’t get that many responses but of those who did most have the same high “interrupt to process” latency.

Anyway I suppose I’m switching back to Windows 10, but I hope this gets solved at some point on Windows 11. I was wondering what you guys and gals think about this. Maybe there is something I overlooked in troubleshooting, or maybe this really is a more widespread issue. And if you want to try, are you able to reproduce this problem on your system?

I’ve attached a screenshot of my results in Windows 11 and Windows 10.

RDT_20230206_1211423569995532705415741
RDT_20230206_12114235699955327054157411124×1021 348 KB

agOhTNr_d

2

Do you have Intel Rapid Storage Technology (Intel RST) installed? That will cause massive DPC latency spikes and audio hitches. Uninstalling RST and reverting the storage driver to the default Microsoft SATA AHCI Controller should fix it.

1 Like
3

I don’t think so, don’t see anything labeled Intel rapid storage in add remove programs or device manager.

4

Could we get some more info on the specific memory kit you are using?

I’m using a 13400f on a MSI B660 and haven’t noticed anything in Windows 10, but 99% of the time I only use it for Steam remote play.

1 Like
5

Yeah, this is the kit I’m using (tried with xmp enabled and disabled). Either configuration I get latency spikes only in Windows 11.

Corsair vengeance 2x16Gb DDR5 5600Mhz:

https://www.corsair.com/ca/en/Categories/Products/Memory/VENGEANCE-DDR5-Memory---Black/p/CMK32GX5M2B5600C36

1 Like
6

What is your current minimum CPU utilization in the windows power plan?
I wonder if there are github scripts that fuzz the Chip so it can’t stall like this, but that’s too beyond my understanding… apologies for terminology.

1 Like
7

I did try setting the power plan to ultimate performance and changing minimum processor state to 100%. This didn’t change anything for me, unfortunately.

8

Windows 11 has a different scheduler vs Windows 10 to account for the difference in “Performance Cores” vs “Efficiency Cores” on the latest gen Intel CPU’s. Maybe you are experiencing this issue due to the processes being run across both Efficiency and Performance cores vs one type exclusively? If you want to give it a try, you can temporarily disable the Efficiency cores in your BIOS. Another way would be to hard set the CPU affinity for the program in question to only execute on the Performance cores. There are a few ways to change the CPU affinity, but the most useful way is to use Process Lasso as you can set profiles for specific apps that will be saved between restarts, etc… Process Lasso lets you set specific cores for exclusively for specific programs, etc., so its really useful (and free).

1 Like
9

I have tried disabling e cores in bios, it didn’t stop the latency spikes unfortunately. Thanks for the info though, process lasso sounds like a useful program.

I have just tried disabling core parking, which I’ve noticed has greatly reduced the rate im getting these spikes, but I’m still getting a spike periodically. (697 after 1 hour. In windows 10 the highest I’ve seen is around 350 after letting run for around 2 hours) Not sure why this would be a cause only in windows 11 for me.

10

Out of curiosity, have you tried applying an affinitymask to the P cores or E cores only and checking again? :thinking:

I was looking into a similar issue within Win11 and Unreal Engine a while back and assigning affinitymasks to coremax-2 resulted in a very large latency drop and a performance uplift in compilation and frametime, weirdly enough. Though, my tests were on a Threadripper and not 13th gen. Just an idea on the whiteboard. :blush:

1 Like
11

What audio interface are you using, and are you using MSI interrupts?

1 Like
12

So I let LatencyMon run over night, highest interrupt to process latency was around 750. I’ll do a test with windows 10 and see if it’s similar. For some reason the regedit to disable parking cores that I’ve seen a few places online, doesn’t actually disable core parking , so I’ve been using quick cpu to do this.

I haven’t tried affinity mask, but not exactly sure how to use affinity masks or even what that means tbh. That would be using something like process lasso to do so? I would guess that I would set it to all p cores and no e cores for a DAW. But I wonder if would I then have to set that for every individual 3rd party vst plugin.

I am using an IK multimedia AXE I/O. But the latency spikes seem to occur with or without it plugged in. I have not used the MSI tool.

I’ll do some work inside my DAW today and see if I have any problems now that core parking is disabled. If I still have some problems I’ll look into affinity masks and MSI tool. Thanks for the info guys.

13

AffinityMasks are instructions to only use select cores for a specific task.

For example, if you had a 8 core CPU with HT, you could instruct it to run on specific cores, including or excluding hyperthreaded cores as you please. This can be done like so:

start /affinity <MASK VALUE> appname.exe

So if you wanted to start let’s say notepad with all cores besides core0+1 on an 8c/16t machine, you could run the following:
My machine is 6c/12t so it lowers down to the highest matching value rather than throwing an error it runs on cores 2-11

start /affinity 0x000000000000FFFC notepad.exe

image
image840×281 20.6 KB

1 Like
14

You can do the affinity mask mentioned above with Process Lasso (done through the GUI - it can also be done so its persistent, or resets after reboots too so its perfect for testing). Coincidentally, Bitsum (the place that makes process lasso) also makes a utility that completely turns off core parking. It even integrates into Process Lasso, which means you can have core parking disable when a specific program launches, but then go back to normal when it terminates, etc…

Lastly, not sure if it has been mentioned already, but would also be a good idea to make sure your power profile is set to the high performance mode…

15

Yep, you can task schedule it to always affinity mask when it launches a specific app, shortcut name, etc.

Lots of goodies in Plasso though :blush:

16

Hi I dont have 13th gen but I’ve been reading a lot about dpc latency lately.

Far and away the biggest improvement for me was enabling MSI mode on my gpu.

I also disabled onboard audio in my bios.

Another thing would be to set your DAW to use maximum performance mode in the nvidia control panel.

You can also use an affinity tool to set your audio interface to use a core other than core 0. But test this both ways as I haven’t proven to myself this is beneficial yet unlike the other changes above which I’ve confirmed by toggling off and on.

I haven’t personally dealt with storport dpc latency so unsure what to do for that one

image
image1170×421 14.4 KB

Windows 11, 528.49 studio nvidia driver

edit:
I think it’s a curse to try help people with DPC latency because since commenting earlier I’ve had multiple spikes to over 3000 interrupt to process latency and dpc routine execution time. So maybe don’t pay any attention to my above advice

17

In my opinion, there is no issue in DPC latency. I haven’t seen any option labeled on Intel storage to add or remove an device or any other software. If it is installed then there ma be a DPC latency issues.

18

I’m also experiencing the same issues on multiples machines (i9 -12900K & i9-13900K) dedicated to audio recording where low latency are requiired.
After weeks of windows reinstalls endless tweaks in both system and bios I finaly managed to get things under control.
here is what worked for me:
in Bios:

  • Disabled all efficient cores
  • Disabled intel turboboost
  • Disabled intel Speedstep
19

This topic was automatically closed 273 days after the last reply. New replies are no longer allowed.