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DPC Latency problem

N

Nackatacka

Member
Joined
Jun 29, 2015
Posts
12
My PC was completely fine until about a week ago. I notice sometimes I was getting bad FPS in games I would always get well over 60. I restarted my PC and it went away. Then it came back when I turned it on again. So I reinstalled Windows and it's still happening. It will do it a lot but sometimes restarting the PC will fix it. I notice my DPC Latency is very high when I am getting the low FPS and audio pops, crackles, and dropouts along with it.
Untitled.jpg
 
Zip up the .etl file, put it on a file share site (OneDrive, DropBox, Google Drive, etc.) and share the link.
 
Driver or hardware? It's strange because I restart my computer and it will go away. But then sometimes it's there.
 
It's the USB3 chipset driver, so likely something attached to a USB3 port. I've seen audio drivers cause that behavior too, but this is specifically the USB3 driver on Windows 7, so it's not native to the OS. Do you have any USB devices attached?
 
cluberti said:
It's the USB3 chipset driver, so likely something attached to a USB3 port. I've seen audio drivers cause that behavior too, but this is specifically the USB3 driver on Windows 7, so it's not native to the OS. Do you have any USB devices attached?
Click to expand...

I recently got a new mouse.
Keyboard
Sound processor thing. USB powered.
 
Start with the most esoteric device, as keyboards and mice don't usually cause issues like that (it's possible, but not likely). Start by removing the sound processing device and see if you can reproduce the issue.
 
cluberti said:
Start with the most esoteric device, as keyboards and mice don't usually cause issues like that (it's possible, but not likely). Start by removing the sound processing device and see if you can reproduce the issue.
Click to expand...

I tried it without these devices and it still happens. This is very strange because my computer was fine and this problem came out of nowhere. A restart of the PC fixes the latency every time though,:huh:
 
Interesting - I see behavior that led me to believe you might now be seeing IRQ sharing - here's all of the things being shared on IRQ 16:
Code: 
PCI Express Controller (PCI\VEN_8086&DEV_0C01&SUBSYS_50001458&REV_06\3&11583659&0&08)
PCI to USB Host Controller (PCI\VEN_8086&DEV_8CAD&SUBSYS_50061458&REV_00\3&11583659&0&D0)
Intel chipset HDAudio Controller (PCI\VEN_8086&DEV_0C0C&SUBSYS_20108086&REV_06\3&11583659&0&18)
Nvidia Geforce GTX 970 (PCI\VEN_10DE&DEV_13C2&SUBSYS_29743842&REV_A1\4&1286464&0&0008)
Intel Chipset Root Port (PCI\VEN_8086&DEV_8C90&SUBSYS_50011458&REV_D0\3&11583659&0&E0)
Nvidia HDAudio Controller (PCI\VEN_10DE&DEV_0FBB&SUBSYS_29743842&REV_A1\4&1286464&0&0108)

In that configuration, I would certainly not be surprised if anything that drives audio or video under load to see interrupt issues. The mainboard chipset, PCI Express controller for one of the x-16 lanes, and both HDAudio options are all on IRQ 16 in this trace. That's... not good. As to the trace, the timeline is very interesting:
02_USB-Network-Disk.png


Recommendations:
1. Update USB3 drivers:
https://downloadcenter.intel.com/download/22824

2. It appears your Intel disk controller is running in IDE emulation mode and not AHCI/RAID (I can tell, there's no ahci driver running and the interrupts on storport are in IDE* functions). There's a trick to swap it without having to reinstall, but IDE emulation is a big perf no-no:
https://support.microsoft.com/en-us/kb/922976

3. Remove the Qualcomm Atheros Bandwidth Control Filter software (aka, "killer network") - bflwfx64.sys, as this is driving interrupt storms as well (and is another known perf no-no). It's actually possible this + USB drivers being out of date are root cause, given the way the KillerService.exe uses CPU for instance. It's been known to cause memory leaks and network perf issues, so I wouldn't keep this on there if I were you.

4. The Corsair RMS link software is consuming 100% on a CPU core 2x in 6 seconds, so unless you're actually using this I'd consider removing it as well. It's not doing you any favors perf-wise.

5. The GeForce experience software is running some binaries that are used in Shield streaming - if you're not using that portion of your card, remove the GeForce Experience software and update manually on a regular basis instead. It consumes CPU at random times that is also not doing you anything if you're not streaming.

All in all, there's a bunch of what I would consider junk software on here I would consider not replacing if you reinstall, if this is a gaming or video PC.
 
Last edited:
What's an alternative for the network driver? Also I think I am gonna just reinstall Windows again and start fresh. Thank you so much for all the help so far.
 

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