Question LatencyMon shows really high latency ?

[specialpants]

i had 2 YouTube videos play in the background when i left idle for almost 3hrs. i also been having some weird audio stutters and distorted noise when playing games and listening to videos/streams. i heard putting my power plan to "high performance can help but i already did that. also up to date on bios and chipset drivers, i don't know what else to do. i am not really good at computers so if anyone has any idea on what i should try please let me know!

7800x3d, gtx 1080, 32gb 6000mhz cl 30

https://imgur.com/a/vUUzKAx

View: https://imgur.com/a/vUUzKAx


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CONCLUSION

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Your system appears to be having trouble handling real-time audio and other tasks. You are likely to experience buffer underruns appearing as drop outs, clicks or pops. One or more ISR routines that belong to a driver running in your system appear to be executing for too long. One problem may be related to power management, disable CPU throttling settings in Control Panel and BIOS setup. Check for BIOS updates.

LatencyMon has been analyzing your system for 2:50:47 (h:mm:ss) on all processors.

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SYSTEM INFORMATION

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Computer name: DESKTOP-2CV3R9O

OS version: Windows 10, 10.0, version 2009, build: 19045 (x64)

Hardware: X670 AORUS ELITE AX, Gigabyte Technology Co., Ltd.

BIOS: F11d

CPU: AuthenticAMD AMD Ryzen 7 7800X3D 8-Core Processor

Logical processors: 16
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CPU SPEED

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Reported CPU speed (WMI): 4201 MHz

Reported CPU speed (registry): 4192 MHz

Note: reported execution times may be calculated based on a fixed reported CPU speed. Disable variable speed settings like Intel Speed Step and AMD Cool N Quiet in the BIOS setup for more accurate results.

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MEASURED INTERRUPT TO USER PROCESS LATENCIES

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The interrupt to process latency reflects the measured interval that a usermode process needed to respond to a hardware request from the moment the interrupt service routine started execution. This includes the scheduling and execution of a DPC routine, the signaling of an event and the waking up of a usermode thread from an idle wait state in response to that event.

Highest measured interrupt to process latency (µs): 50176.80

Average measured interrupt to process latency (µs): 3.903489

Highest measured interrupt to DPC latency (µs): 50167.40

Average measured interrupt to DPC latency (µs): 1.472412

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REPORTED ISRs

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Interrupt service routines are routines installed by the OS and device drivers that execute in response to a hardware interrupt signal.

Highest ISR routine execution time (µs): 25808.398855

Driver with highest ISR routine execution time: dxgkrnl.sys - DirectX Graphics Kernel, Microsoft Corporation

Highest reported total ISR routine time (%): 0.052983

Driver with highest ISR total time: dxgkrnl.sys - DirectX Graphics Kernel, Microsoft Corporation

Total time spent in ISRs (%) 0.058373

ISR count (execution time <250 µs): 10548713

ISR count (execution time 250-500 µs): 0

ISR count (execution time 500-1000 µs): 31

ISR count (execution time 1000-2000 µs): 0

ISR count (execution time 2000-4000 µs): 0

ISR count (execution time >=4000 µs): 0

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REPORTED DPCs

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DPC routines are part of the interrupt servicing dispatch mechanism and disable the possibility for a process to utilize the CPU while it is interrupted until the DPC has finished execution.

Highest DPC routine execution time (µs): 618.979008

Driver with highest DPC routine execution time: nvlddmkm.sys - NVIDIA Windows Kernel Mode Driver, Version 545.92 , NVIDIA Corporation

Highest reported total DPC routine time (%): 0.019450

Driver with highest DPC total execution time: dxgkrnl.sys - DirectX Graphics Kernel, Microsoft Corporation

Total time spent in DPCs (%) 0.040189

DPC count (execution time <250 µs): 20141359

DPC count (execution time 250-500 µs): 0

DPC count (execution time 500-10000 µs): 4

DPC count (execution time 1000-2000 µs): 0

DPC count (execution time 2000-4000 µs): 0

DPC count (execution time >=4000 µs): 0

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REPORTED HARD PAGEFAULTS

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Hard pagefaults are events that get triggered by making use of virtual memory that is not resident in RAM but backed by a memory mapped file on disk. The process of resolving the hard pagefault requires reading in the memory from disk while the process is interrupted and blocked from execution.

NOTE: some processes were hit by hard pagefaults. If these were programs producing audio, they are likely to interrupt the audio stream resulting in dropouts, clicks and pops. Check the Processes tab to see which programs were hit.

Process with highest pagefault count: fontdrvhost.exe

Total number of hard pagefaults 22708

Hard pagefault count of hardest hit process: 7235

Number of processes hit: 45

Spoiler

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PER CPU DATA

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CPU 0 Interrupt cycle time (s): 228.008265

CPU 0 ISR highest execution time (µs): 25808.398855

CPU 0 ISR total execution time (s): 95.673989

CPU 0 ISR count: 10461141

CPU 0 DPC highest execution time (µs): 618.979008

CPU 0 DPC total execution time (s): 63.785131

CPU 0 DPC count: 19161326

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CPU 1 Interrupt cycle time (s): 5.306298

CPU 1 ISR highest execution time (µs): 8.496183

CPU 1 ISR total execution time (s): 0.000593

CPU 1 ISR count: 311

CPU 1 DPC highest execution time (µs): 75.123092

CPU 1 DPC total execution time (s): 0.003998

CPU 1 DPC count: 1160

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CPU 2 Interrupt cycle time (s): 16.198003

CPU 2 ISR highest execution time (µs): 7.674618

CPU 2 ISR total execution time (s): 0.000158

CPU 2 ISR count: 28

CPU 2 DPC highest execution time (µs): 209.128340

CPU 2 DPC total execution time (s): 1.064058

CPU 2 DPC count: 610175

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CPU 3 Interrupt cycle time (s): 8.004420

CPU 3 ISR highest execution time (µs): 0.0

CPU 3 ISR total execution time (s): 0.0

CPU 3 ISR count: 0

CPU 3 DPC highest execution time (µs): 209.048187

CPU 3 DPC total execution time (s): 0.101212

CPU 3 DPC count: 49241

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CPU 4 Interrupt cycle time (s): 6.922696

CPU 4 ISR highest execution time (µs): 0.0

CPU 4 ISR total execution time (s): 0.0

CPU 4 ISR count: 0

CPU 4 DPC highest execution time (µs): 97.625954

CPU 4 DPC total execution time (s): 0.023925

CPU 4 DPC count: 11188

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CPU 5 Interrupt cycle time (s): 4.252807

CPU 5 ISR highest execution time (µs): 0.0

CPU 5 ISR total execution time (s): 0.0

CPU 5 ISR count: 0

CPU 5 DPC highest execution time (µs): 9.117366

CPU 5 DPC total execution time (s): 0.000430

CPU 5 DPC count: 272

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CPU 6 Interrupt cycle time (s): 9.674360

CPU 6 ISR highest execution time (µs): 0.0

CPU 6 ISR total execution time (s): 0.0

CPU 6 ISR count: 0

CPU 6 DPC highest execution time (µs): 166.968034

CPU 6 DPC total execution time (s): 0.273729

CPU 6 DPC count: 98553

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CPU 7 Interrupt cycle time (s): 10.111106

CPU 7 ISR highest execution time (µs): 0.0

CPU 7 ISR total execution time (s): 0.0

CPU 7 ISR count: 0

CPU 7 DPC highest execution time (µs): 177.528149

CPU 7 DPC total execution time (s): 0.309360

CPU 7 DPC count: 109065

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CPU 8 Interrupt cycle time (s): 5.685052

CPU 8 ISR highest execution time (µs): 0.0

CPU 8 ISR total execution time (s): 0.0

CPU 8 ISR count: 0

CPU 8 DPC highest execution time (µs): 53.632156

CPU 8 DPC total execution time (s): 0.009356

CPU 8 DPC count: 4068

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CPU 9 Interrupt cycle time (s): 3.128404

CPU 9 ISR highest execution time (µs): 0.0

CPU 9 ISR total execution time (s): 0.0

CPU 9 ISR count: 0

CPU 9 DPC highest execution time (µs): 22.062023

CPU 9 DPC total execution time (s): 0.001034

CPU 9 DPC count: 454

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CPU 10 Interrupt cycle time (s): 10.549063

CPU 10 ISR highest execution time (µs): 0.0

CPU 10 ISR total execution time (s): 0.0

CPU 10 ISR count: 0

CPU 10 DPC highest execution time (µs): 54.383588

CPU 10 DPC total execution time (s): 0.258697

CPU 10 DPC count: 75754
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CPU 11 Interrupt cycle time (s): 4.855562

CPU 11 ISR highest execution time (µs): 0.0

CPU 11 ISR total execution time (s): 0.0

CPU 11 ISR count: 0

CPU 11 DPC highest execution time (µs): 200.381679

CPU 11 DPC total execution time (s): 0.002531

CPU 11 DPC count: 745

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CPU 12 Interrupt cycle time (s): 7.784630

CPU 12 ISR highest execution time (µs): 5.911260

CPU 12 ISR total execution time (s): 0.024435

CPU 12 ISR count: 62336

CPU 12 DPC highest execution time (µs): 194.290076

CPU 12 DPC total execution time (s): 0.022321

CPU 12 DPC count: 6588

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CPU 13 Interrupt cycle time (s): 5.471741

CPU 13 ISR highest execution time (µs): 2.314408

CPU 13 ISR total execution time (s): 0.002603

CPU 13 ISR count: 6281

CPU 13 DPC highest execution time (µs): 40.256679

CPU 13 DPC total execution time (s): 0.007053

CPU 13 DPC count: 3703

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CPU 14 Interrupt cycle time (s): 6.740148

CPU 14 ISR highest execution time (µs): 10.790553

CPU 14 ISR total execution time (s): 0.007963

CPU 14 ISR count: 18160

CPU 14 DPC highest execution time (µs): 89.119752

CPU 14 DPC total execution time (s): 0.031861

CPU 14 DPC count: 8645

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CPU 15 Interrupt cycle time (s): 4.031068

CPU 15 ISR highest execution time (µs): 2.414599

CPU 15 ISR total execution time (s): 0.000209

CPU 15 ISR count: 488

CPU 15 DPC highest execution time (µs): 31.299618

CPU 15 DPC total execution time (s): 0.001572

CPU 15 DPC count: 426

 

[ubuysa]

A quick overview of device interrupts might help here...

When a device has completed whatever task it was given it raises an interrupt. This interrupts one of the processors which identifies what device has raised the interrupt and then gives control to the device's Interrupt Service Routine (ISR). The ISR code is part of the driver and all it does is tell the device we received the interrupt, schedule a DPC (Deferred Procedure Call) to handle the bulk of the interrupt work (DPCs are placed on a queue for execution later), and it then returns control back to whatever was interrupted. ISRs thus typically execute very quickly.

When a processor has no other work to do it executes the DPC queue to run all the scheduled DPCs. The DPC is where the real interrupt work is done, reading the input buffer for example, telling the waiting program where that buffer is, and marking the waiting app as ready to execute again. The DPC code is also part of the device driver for the specific device.

Typically the ISR is a tiny component of the overall device interrupt time (the latency) and the DPC is the largest (because it does the real work). In your case however, the biggest component is the ISR time and that's unusual. LatencyMon is flagging dxgkrnl.sys as the problem driver, but that's a Windows DirectX driver and it's not this driver's ISR that will be run, dxgkrnl.sys will call the lower-level graphics driver (nvlddmkm.sys) and run the ISR in there.

You can also see that LatencyMon is flagging nvlddmkm.sys as having the longest running DPC too, although the impact of this is not as great as the ISR.

For the ISR to take so long I would suspect a hardware problem with the graphics card. The ISR code in the driver (nvlddmkm.sys) is very unlikely to be a problem. However, laptops are very fussy about their graphics drivers, they are often customised for the specific laptop for operational, performance, and/or power-saving reasons. Because of this, generic graphics drivers from Nvidia, which don't contain the required customisation, sometimes don't work properly.

I suggest you download the graphics driver for your laptop from the laptop vendors website - even if it is old. Use DDU to uninstall the existing graphics driver and install the vendor's downloaded driver. See whether it's stable with that driver.

In addition, look in all of the sub-folders under the folder C:\Windows\LiveKernelReports, if you find .dmp files in any of those sub-folders please upload them to the cloud with a link to them here (be sure to make them public). These folders are where Windows writes dump files for problems that were recovered, we might see some clues in there.

 

[specialpants]

A quick overview of device interrupts might help here...

When a device has completed whatever task it was given it raises an interrupt. This interrupts one of the processors which identifies what device has raised the interrupt and then gives control to the device's Interrupt Service Routine (ISR). The ISR code is part of the driver and all it does is tell the device we received the interrupt, schedule a DPC (Deferred Procedure Call) to handle the bulk of the interrupt work (DPCs are placed on a queue for execution later), and it then returns control back to whatever was interrupted. ISRs thus typically execute very quickly.

When a processor has no other work to do it executes the DPC queue to run all the scheduled DPCs. The DPC is where the real interrupt work is done, reading the input buffer for example, telling the waiting program where that buffer is, and marking the waiting app as ready to execute again. The DPC code is also part of the device driver for the specific device.

Typically the ISR is a tiny component of the overall device interrupt time (the latency) and the DPC is the largest (because it does the real work). In your case however, the biggest component is the ISR time and that's unusual. LatencyMon is flagging dxgkrnl.sys as the problem driver, but that's a Windows DirectX driver and it's not this driver's ISR that will be run, dxgkrnl.sys will call the lower-level graphics driver (nvlddmkm.sys) and run the ISR in there.

You can also see that LatencyMon is flagging nvlddmkm.sys as having the longest running DPC too, although the impact of this is not as great as the ISR.

For the ISR to take so long I would suspect a hardware problem with the graphics card. The ISR code in the driver (nvlddmkm.sys) is very unlikely to be a problem. However, laptops are very fussy about their graphics drivers, they are often customised for the specific laptop for operational, performance, and/or power-saving reasons. Because of this, generic graphics drivers from Nvidia, which don't contain the required customisation, sometimes don't work properly.

I suggest you download the graphics driver for your laptop from the laptop vendors website - even if it is old. Use DDU to uninstall the existing graphics driver and install the vendor's downloaded driver. See whether it's stable with that driver.

In addition, look in all of the sub-folders under the folder C:\Windows\LiveKernelReports, if you find .dmp files in any of those sub-folders please upload them to the cloud with a link to them here (be sure to make them public). These folders are where Windows writes dump files for problems that were recovered, we might see some clues in there.

i have a desktop not a laptop and i think i fixed it by disabling cpu c states

 

[Colif]

From the times I have seen this run, Nvidia is always at top... I think its actually normal and not a sign of it being Nvidia. It can be a driver but just cause Nvidia is on top, doesn't mean its to blame

some of these can help

 

[ubuysa]

That might be because the Nvidia driver is almost always the problem! 🤣

 

[specialpants]

That might be because the Nvidia driver is almost always the problem! 🤣

Yeah, I ran latencymon for like 6hrs and its completely fine now after disabling cpu c states, weird.

 

[ubuysa]

Yeah, I ran latencymon for like 6hrs and its completely fine now after disabling cpu c states, weird.

Disabling C States prevents the processors from entering a low power state when idle. It's possible that the ISR was taking too long because the processor handling it was slow coming out of the low power state....? That's the only thing I can think that explains what you're seeing.

Have you ever seen a CLOCK_WATCHDOG_TIMEOUT BSOD? That's a common BSOD when processors struggle with low power states. I've seen it more than once on AMD processors, less so on Intel processors. There's no way to 'fix' that so disabling C States is the best workaround.

 

[specialpants]

Disabling C States prevents the processors from entering a low power state when idle. It's possible that the ISR was taking too long because the processor handling it was slow coming out of the low power state....? That's the only thing I can think that explains what you're seeing.

Have you ever seen a CLOCK_WATCHDOG_TIMEOUT BSOD? That's a common BSOD when processors struggle with low power states. I've seen it more than once on AMD processors, less so on Intel processors. There's no way to 'fix' that so disabling C States is the best workaround.

I have never seen that BSOD before on my pc. Is there any downside of disabling C states?

 

[ubuysa]

The only downside is an increase in power usage and higher idle temps. That's often unwanted in a laptop but in a desktop it's of no real significance.