High DPC Latency - UNKNOWN appears in driver report

deleted03202021 · Jun 24, 2013

Hi everyone, I find this forum when searching for cures for my DPC latency issues and came across this great tutorial:

https://www.sysnative.com/forums/wi...y-issues-wpa-windows-windows-vista-7-8-a.html

I've been experiencing some annoying audio dropouts when playing back through WMP, Chrome etc. Here is my DPCLC report:

I followed the tutorial above and produced a Windows Performance Analysis report, there seems to be one driver in particular with a much higher duration than others but under the module tab its just listed as 'Unknown':

Therefore I'm not sure how to solve my issue as I can't identify what's causing my DPC spikes or even if this Unknown one is solely responsible. Any help would be greatly appreciated, my system spec is:

Windows 7 64-bit PRO
Gigabyte EX58-UD5
Intel 920 D0
OCZ 12GB
OCZ Vertex 4 256GB SSD
Enermax Modu 87 PSU
AMD HD6670 GPU

satrow · Jun 25, 2013

Hi and Welcome to Sysnative willsium!

'Unknown' makes me think the driver isn't verified and could be corrupt or otherwise 'interfered' with, possibly by malware or a different, bad, driver. Does LatencyMon show this driver, any further details given for it?

deleted03202021 · Jun 28, 2013

Thanks satrow, I've just run latency mon and here are the results:

Can't seem to even see Unknown in the list. Any ideas?

satrow · Jun 28, 2013

The highest count driver listed there that isn't in the original (ignoring the monitoring software drivers) appears to be i8042prt.sys, the PS/2 mouse/keyboard port driver, what keyboard and mouse are you using? Do you have alternatives or USB versions to test with?

It may be that there's a corrupted or infected driver, could youi run through the steps here and have the logs checked over: https://www.sysnative.com/forums/security-arena/2507-malware-removal-posting-instructions.html?

deleted03202021 · Jul 2, 2013

I'm using an old Logitech Mx mouse and a newer microsoft Wireless mobile 3500 mouse with an Apple wired keyboard, the logitech uses the PS2 port. In the latency mon report which column am I supposed to be looking at as some seem to have a high results in one but not the other. Thanks again for the help.

satrow · Jul 2, 2013

I'd shutdown, remove the MX mouse, restart and run all the tests again to look for differences, also check the audio output in WMP/Chrome. The column to look at in LatencyMon/Drivers is Total execution, which should I think, equate to the Actual duration column in the WPA report.

Search

Search

High DPC Latency - UNKNOWN appears in driver report

deleted03202021

New member

satrow

Moderator, BSOD Kernel Dump Senior Analyst

deleted03202021

New member

satrow

Moderator, BSOD Kernel Dump Senior Analyst

deleted03202021

New member

satrow

Moderator, BSOD Kernel Dump Senior Analyst