Ryzen 5900x + Geforce 3080 on Win 11, had massive DPC spikes, now fixed!

Cubase
1

  1. Hi,
    (Steingberg UR22 on USB)

    Just wanted to tell a sunshine story :slight_smile: I have had DPC/glitches and noise from time to time on my machine. This weekend I gave it my full attention and I sorted it

    1. Installed new chipset drivers for my motherboard. MSI Tomahawk x570
    2. Installed new NIC/network driver from realteks homepage(check your model)
    3. Updated win 11 to newest 25h2
    4. rebooted
    5. Downloaded latest Studio driver from Nvidia - choose install and ticked “clean install”
    6. Reboot
    7. Changed these settings in the Nvidia control panel. Power management - set it to Performance. Latency(nvidia control panel), set it to “Ultra”
    8. Earlier I have enabled Ultimate Performance power profile in Win 11 - don’t know if that is needed(this is a desktop computer, always connected to AC)

    Now I can run the LatencyMon - dpc check forever without and hiccups!

    So happy!

    Cheers,

    Lazze

4 Likes
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The Studio nVidia driver is the key. And using the Ultimate Performance power plan will reduce core parking/waking times, also helping with latency. You might also want to check out MSI Utility to check on the interrupts for your hardware - there might be some you can switch to MSI mode (rather than legacy interrupts) to get further improvements. Nice to hear a success story!

1 Like
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For Windows 11, I generally recommend trying to avoid the legacy power plans and use “Best Performance” in the Settings app, if you can.

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Pete
Microsoft

3 Likes
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That is good input! Thanks

// Lazze

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Yeah - I checked with the MSI(IRQ) util and Nvidia was using MSI already - I believe this is the case for many modern computers running Win11

Cheers,

Lasse

6

What is DPC?

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That questions opens a can of worms :slight_smile:

Basically, DPC(Deferred procedure call) is a way for a devices saying “I got data that I want to send”(IRQ in the old days). A graphicscard have lots of data to send so it can hog the CPU for too long(especially the first core of the CPU) - resulting in that there is no CPU time to process the audio, giving us a sound glitch or noise.

// Lazze

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How do you observe DPC activity?

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Your hear it with your hears, like crackle and pops when playing VST instruments

There is also a util that you get here: Resplendence Software - LatencyMon: suitability checker for real-time audio and other tasks

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Primary sources of DPC latency these days:

  • GPUs that are gamer-optimized. (Which is why nvidia Studio drivers are preferred for musicians)
  • WiFi when you don’t have a good signal, so there are lots of retries.
  • Gamer network optimizers
  • Hardware faults or just drivers that don’t play well with others. Some gamer light-show drivers have shown this.
  • Some power management events

All DPCs are kernel calls, so they’re almost always a driver of some sort. DPCs themselves are not a bad thing – they are a standard practice. It’s only when the owner of the DPC fails to complete in the time allowed that we see problems.

DPCs (and therefore DPC latency) is per-core. A driver on Core 4 is not going to impact audio that’s on Core 1. So if you have a must-have driver that is misbehaving, and there’s no update available, you can usually use a third-party tool to force it to stay on some other core, and then use that tool to exclude audio workloads from that core. This is a somewhat extreme circumstance, and something hardly anyone actually needs to do, but it’s a way out when needed.

Pete
Microsoft

6 Likes
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It’s so great to make music on Cubase, one day!

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Just a note about the Nvidia ‘Studio drivers’: always install the latest official Windows update, never update through the app, just trust Windows and the certifications.

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Ideally you should also be using the Power Plan profiles provided by AMD, not the Win11 ones.

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Ideally you should also be using the Power Plan profiles provided by AMD, not the Win11 ones.

Those are often very gamer-oriented, so buyer beware.

Also, I do recommend people use the much simpler Win 11 power setting in Settings before considering messing with individual power plans.

YMMV based on type of CPU, its architecture, and how it’s set up on the motherboard and BIOS.

Pete
Microsoft

15

This cured my issues with NVIDIA (even Studio) drivers causing audio problems:
Solving Audio Dropouts / DPC Latency Issues With NVIDIA Drivers On Windows
@Psychlist1972 Hi Pete, re. the MS Interrupt-Affinity tool, what’s your take on this please?

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As a last resort, if it works, great. But it’s papering over whatever the actual problem is. The NVIDIA driver shouldn’t take 4ms to do something. I know that’s nothing you control, but it makes me wonder if something was buggy with that version of the driver, if the GPU isn’t quite up to the current task, or something is failing in the HW.

The challenge with tools like this is they really lead you down a rabbit hole. Once you start isolating different things to different cores, you really start restricting what the system can do, and what your apps can run on. No one should have to think this hard about their system internals.

But, like I said, if it works for you, great. Just not something I’d start with.

Pete
Microsoft

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Could you explain a bit what is the difference? I did some testing in Cubase 14 and saw no difference between Best Performance setting and legacy High Performance plan.