Very High DPC Latency - Need Advice

Fazzar

Limp Gawd
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Aug 22, 2004
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I've been trying to troubleshoot crackling/popping sound problems on my newly built rig (details in sig). In my reading I came across the DPC Latency Checker and saw that I've got some extremely high and consistent system latency. I've updated every driver I can think of, including trying a few different Realtek drivers. I've updated my BIOS to the most recent version. I've also tried disabling as many devices as I dare to try to pinpoint the latency culprit.

Any ideas on how to identify the problem? I'm assuming I have some sort of conflict.


 

Joe Average

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I know this might catch me some flack (hell, every time my fingers hit the keys that's an issue) but... have you considered a clean install, unless this is such a beast done within the past few days?

And if it's not a clean install, would you be willing to back your current install up (make an image of it so you can restore it perfectly), and then do a clean install for testing, a driver at a time?

That would be my highest recommendation: start clean (even if it's just a test), and do a DPC check after every single step along the way:

1) Clean install, first actual boot to the working Desktop, do a DPC check and record results.
2) Hit Windows Update and get a driver at a time - don't do all of them at one time, just add one driver at a time (they'll be under the Optional components), reboot if required, check DPC on the reboot, move to the next driver, etc
3) Keep going till all the hardware has the latest driver(s) from Windows Update - don't use drivers that came on a CD or DVD with the hardware, don't download drivers from the manufacturer of the hardware either. Use ONLY the drivers from Windows Update unless for some reason there isn't one.
4) Once you've gone through that process and everything is fully supported by a Windows Update driver (if possible, per #3 above), then you can try and install a driver that could be a more current one (based on version number) or a more full-featured one - typically that means video drivers since those are arguably the most updated ones on modern computers.
5) If you get through all this and absolutely nothing seems to cause the DPC to get up to the same levels, then I'd say enjoy your "clean" install and make good use of it. If you get that level of latency from the gitgo, I'd suspect either something being horribly wrong with the OS itself, a potential driver conflict that you're not likely to track down, or the mobo could have some defect that, again, you're not likely to track down.

That's what I'd do if my machine had that kind of latency. Yes, it's a somewhat complicated process to get it resolved but, if it does get resolved, then it's worth it. That's the worst DPC latency I've ever seen, and it's not a random thing either - it's nearly solid so something obviously is terribly wrong with that box (which you already know). :p
 

Fazzar

Limp Gawd
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Aug 22, 2004
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290
I'm going to hold off on a clean install, I have slow DSL and it takes me forever to get things up and running.

I ran LatencyMon. What am I looking for in here. Is MsMpEng.exe the problem?

One or more DPC and ISR routines that execute on behalf of drivers running in your system appear to be causing serious problems making your system unsuitable for processing real time audio. You are likely to experience audio dropouts, clicks and pops.
Time running: 0:02:11




Highest DPC routine execution time (µs): 10036
Responsible driver: SCSIPORT.SYS (SCSI Port Driver, Microsoft Corporation)
DPC count (execution time <500 µs): 11593844
DPC count (execution time 500-999 µs): 0
DPC count (execution time 1000-1999 µs): 0
DPC count (execution time 2000-3999 µs): 0
DPC count (execution time >=4000 µs): 4

Highest ISR routine execution time (µs): 10064
Responsible driver: SCSIPORT.SYS (SCSI Port Driver, Microsoft Corporation)
ISR count (execution time <250 µs): 6988608
ISR count (execution time 250-499 µs): 0
ISR count (execution time 500-999 µs): 0
ISR count (execution time 1000-1999 µs): 0
ISR count (execution time >=2000 µs): 176357

Highest pagefault resolution time (µs): 11194
Hard pagefault count (total): 54101
Number of processes hit: 3
Pagefault count of hardest hit process: 50109
Process with highest pagefault count: MsMpEng.exe (PID: 984)

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.

Note: all execution times are calculated based on a fixed CPU clock speed of 3411 MHz. Disable variable speed settings like Intel Speed Step and AMD Cool N Quiet in the BIOS setup for more accurate results.
 

Snowknight26

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Definitely an issue wtih the SCSI port driver. Aside from updating it, don't really know what else to tell you.

I recently had a similar issue with the ATAPI driver; disabling the SATA3 ports in the BIOS fixed the high DPC/interrupts. Maybe that'd be worth looking into, but who knows.
 

Fazzar

Limp Gawd
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Aug 22, 2004
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290
Thanks. How do I update the SCSI port driver. And what does it do?

Is it possible when I built this thing I plugged a SATA3 in the wrong spot somehow on the board? I have a SSD, a regular HD and a Blu-Ray burner, they work, but maybe I connected something wrong?

I uninstalled Microsoft Security Essentials because that was showing up, but the latency is still there:

Highest DPC routine execution time (µs): 10049
Responsible driver: dxgkrnl.sys (DirectX Graphics Kernel, Microsoft Corporation)
DPC count (execution time <500 µs): 16716697
DPC count (execution time 500-999 µs): 0
DPC count (execution time 1000-1999 µs): 0
DPC count (execution time 2000-3999 µs): 0
DPC count (execution time >=4000 µs): 228

Highest ISR routine execution time (µs): 10079
Responsible driver: SCSIPORT.SYS (SCSI Port Driver, Microsoft Corporation)
ISR count (execution time <250 µs): 4048959
ISR count (execution time 250-499 µs): 0
ISR count (execution time 500-999 µs): 0
ISR count (execution time 1000-1999 µs): 0
ISR count (execution time >=2000 µs): 82980

Highest pagefault resolution time (µs): 3
Hard pagefault count (total): 4
Number of processes hit: 1
Pagefault count of hardest hit process: 4
Process with highest pagefault count: mvraidsvc.exe (PID: 2200, Marvell Storage Service, Marvell)
 

Fazzar

Limp Gawd
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Aug 22, 2004
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290
I tried booting in Safe Mode with Networking. The latency was gone. I still can't figure out a fix though.
 

Fazzar

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Well, I uninstalled the AISuite and that didn't make a difference. HOWEVER, on another thread where I was looking for ideas on specifically the latency issue, someone recommend that I keep a disc in the optical drive at all times. And you know what, it actually worked!! And my resolving that latency issue, no more crackling/popping with the sound.

What the heck is going on that requires me to have a disc in my blu-ray player to solve my latency issue??

 

Joe Average

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/me is officially stumped...

But I would suspect what Snowknight26 mentioned since it's so obvious based on the results you posted: there's something funky with that SCSI device. Could be some kind of conflict with the Blu-ray drive's SATA channel and the SATA controller (since SATA controllers are 'seen' by the OS as SCSI-style hardware). It might have some issue making it "stuck" on notifying the OS that there's no disc in the drive; you might consider disabling AutoPlay (and AutoRun too, done with a Group Policy edit - AutoPlay and AutoRun are not the same thing). AutoPlay looks for an .inf on inserted devices (if it's enabled); AutoRun checks/polls optical drives every second or so to see if the drive is trying to notify the OS that "hey, I just got a disc inserted, do you want me to spin it up and let you look for that .inf?" in principle.

Have you attempted to just physically disconnect the Blu-ray drive (both power and SATA connection) and then check DPC again to see if that truly is the actual cause of the high latency? If it is, then that's the suspect device; if a firmware update exists (which you've probably already done or checked on) it may offer some hope for a resolution.

I still say image the whole system partition and do a clean install, but that's just me and how I troubleshoot stuff: one single step at a time and test between each step to figure out the who/what/when/why/how...
 

Tawnos

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Could be that the drive is attempting to read a disc and blocking until return. Just a guess.
 

bigdogchris

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Remember that a lot of add-on controllers, like Marvel sata ports, do not support ATAPI (optical drives). Make sure the SATA connector for the optical drive is plugged into a native sata port on the motherboard. On your motherboard, the dark blue are Marvel. If it's plugged in there, that could be the issue. Move it to the gray or light blue ports.

Those types of drives have some type of 'stay alive' command, or something like that, that monitors the disc status. Keeping a disc in the drive likely gives back some type of signal that an empty drive bay does not. The signal that it's empty is probably why they are not compatible with the Marvel controllers.
 

Jon55

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I've seen this come up before. What exactly is DPC Latency? What makes it bad?
 

Demon10000

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http://www.thesycon.de/deu/latency_check.shtml

If any kernel-mode device driver in your Windows system is implemented improperly and causes excessive latencies of Deferred Procedure Calls (DPCs) then probably drop-outs will occur when you use real-time audio or video streaming applications. For an explanation of this effect see Background information below.

The DPC Latency Checker tool determines the maximum DPC latency that occurs on your Windows system and thus enables you to check the real-time capabilities of your computer. DPC Latency Checker works independent of any external hardware. Using this tool may be helpful in the following situations:
  • You experience interruptions (drop-outs) in a flow of data processed in real-time, for example an audio stream, video stream or a sequence of measuring data, and you want to find out the reason for this problem.
  • You want to verify that your Windows system is configured properly so that it is capable of handling real-time data transfer before you install the corresponding streaming application.
  • You want to check if a particular computer system is suitable for streaming applications, for example before you buy this system.
For more information on the Deferred Procedure Call mechanism and how an excessive DPC latency will affect a streaming application see Background information below.
 

Ranma_Sao

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MSMPENG.EXE is going to hard fault like crazy, that's totally by design...

(It scan's processes, and is going to have to page in the full process to scan it, thus it's going to page fault, it's totally by design.)

This post is made "AS IS" without warranties, and confers no rights
 

evilsofa

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For those who don't know, when Ranma_Sao talks about how MSE is designed, he's in a position to know. ;)
 

Fazzar

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MSMPENG.EXE is going to hard fault like crazy, that's totally by design...

(It scan's processes, and is going to have to page in the full process to scan it, thus it's going to page fault, it's totally by design.)

This post is made "AS IS" without warranties, and confers no rights


Thanks. So, is there a solultion to this other than leaving a DVD in the opitcal drive? You make it sound like this is just the way it is, but I could be reading it wrong.
 

Tawnos

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Thanks. So, is there a solultion to this other than leaving a DVD in the opitcal drive? You make it sound like this is just the way it is, but I could be reading it wrong.

This actually appears to be due to a driver issue. He was steering you away from mistakenly pointing a finger at the malware scanning engine. If you haven't tried a different SATA port, as suggested by bigdogchris, I would start there.
 

Fazzar

Limp Gawd
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ah yes. I've reinstalled Malware and I've reinstalled Microsoft Security Essentials and my DPC latency is very low still.... as long as I keep something in my Optical Drive :)

This weekend, I will switch around the SATA port and see if that does the trick. If not, I'll like at the firmware for the optical drive.
 

lazenby

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Nov 17, 2011
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Hi

I was earlier running Windows Vista without any issues. I recently replaced my hard drive and installed Windows 7. I downloaded and installed all the drivers from HP website. However, the laptop becomes insane slow when I open a few tabs on Chrome or play a video from Youtube etc.

I ran DPC Latency Checker and LatencyMon. Directx Graphics Kernel (dxgkrnl.sys) shows the highest execution at 17.6ms while NDIS 6.20 (ndis.sys) shows the second highest execution time at 2ms. The others were well within 500microsec.

I have DirectX 11 installed on my system. Please suggest me a solution. Would I be better off with Vista??
 
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I know this was posted a long time ago but I was having the same issues with my Internal Blu Ray player as well. Very High Latency after installing Window 10. (Never had any trouble before with Win 7 ). I narrowed it down to my Blu Ray by disabling various Drivers in Device Manager with Latency Monitor running. When I disabled the player the problem went away. I was pulling my hair out trying different things. I found this forum and when I inserted a disc like Fazzar did, my High Latency dropped to around 30us from 250000us. It turned out to be the SATA port I was using for the drive on my ASUS Z87 Pro Mother Board. The port I was using was one of the Brown ones and reading the manual it states Data Drives Only. Once I transferred it to another port (Yellow) the issue was gone. Hope this helps someone if they ever run into the same issue as I couldn't find anything else on the web. Thank you to bigdogchris for the port suggestion, and to Fazzar regarding inserting a disc.
 

vick1000

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What's an optical drive? Is that some new tech from the Vulcans for space travel?
 

bman212121

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I didn't see this thread the first time around, but I've noticed higher latency on Windows 10 than I used to see in older OSes like XP. This might be a blast from the past but certainly an intriguing idea to check the disc drive to see if that's what's causing latency. I would have never thought of that as being the problem.
 

B00nie

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I have an optical hole where the drive used to go. No wonder my computar feels fast like a black hole!
 
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