[How to get the cause of high CPU usage by DPC / Interrupt]

I've fixed this now. Quite separately I had a problem with low (less than 500k) network throughput. After having tried various remedies I found that setting my card from 'Auto' to '100M full duplex' solved the problem. Since then I've also had no further problems with dwm and high cpu / dpc.

[How to get the cause of high CPU usage by DPC / Interrupt]

OK and thanks for all your help. 

[How to get the cause of high CPU usage by DPC / Interrupt]

try a better/faster card

 

Thanks a ton for deciphering the cause. Really frustrating. I find it almost unbelievable that MS ships a product that can't use it as, to quote PassMark, "The low to mid range chart typically contains video cards that are a couple of years old and includes . . . better performing Integrated Display Adapters from Intel, Asus and other manufacturers."

 

Anyway PassMark gives the GeForce 210 a score of 184 which is half way down the chart. How much faster do I need to go?

 

Andy

PS. Found this thread with similar issues to mine and which I see you contributed to. https://social.technet.microsoft.com/Forums/windows/en-US/6884366d-6759-4ab9-89c5-fd6af8008b28/dwmexe-starts-consuming-lots-of-cpu-when-machine-is-idle?forum=w8itproperf

[How to get the cause of high CPU usage by DPC / Interrupt]

Andre

 

Here it is.

 

https://drive.google.com/file/d/0B519kC-I-qWkLXBkVUEwR3FySWc/view?usp=sharing

 

Andy

 

 

[How to get the cause of high CPU usage by DPC / Interrupt]

Hi Andre I hope you can help me. I installed Win8.1 x64 on my 4 core 16GB machine (c 2007) and since then have had dwm.exe exhibit 20% CPU for a couple of minutes every 7 mins or so. My machine is normally fine for the first day after a reboot but it gets steadily worse. Shutting down Outlook seems to immediately stop dwm's high CPU but it may be memory related (even though I rarely exceed 12GB) or GDI as sometimes shutting down Chrome (with typically 20+ windows open) also does the same. I also normally have 15+ applications running concurrently. I have just replaced the GE7300 with a GE210 and it made no difference.

 

I started researching this a month or so ago and have used LatenecyMon and xperf. They both point to nvlddmkm.sys being the culprit.

 

Here's an edited xperf showing the modules with >256us. This trace was taken during one of the high CPU dwm periods.

 

Total = 11946 for module ndis.sys

Elapsed Time, >      256 usecs AND <=      512 usecs,     11, or   0.09%

 

Total = 100191 for module nvlddmkm.sys

Elapsed Time, >      256 usecs AND <=      512 usecs,     61, or   0.06%

Elapsed Time, >      512 usecs AND <=     1024 usecs,     19, or   0.02%

 

Total = 11048 for module tcpip.sys

Elapsed Time, >      256 usecs AND <=      512 usecs,      2, or   0.02%

 

The GUI shows the following have greater than 0.01% duration:

nvlddmkm.sys 0.11%

dxgkrnl.sys 0.07%

USBPORT.SYS 0.07%

tcpip.sys 0.07%

ataport.SYS 0.02%

ndis.sys 0.02%

afd.sys 0.01%

VBoxDrv.sys 0.01%

ntoskrnl.exe 0.01%

 

And relevant LatencyMon output (taken at a different time of course):

 

Highest DPC routine execution time (µs):              93661.044123

Driver with highest DPC routine execution time:       nvlddmkm.sys - NVIDIA Windows Kernel Mode Driver, Version 341.44 , NVIDIA Corporation

 

Highest reported total DPC routine time (%):          0.137717

Driver with highest DPC total execution time:         nvlddmkm.sys - NVIDIA Windows Kernel Mode Driver, Version 341.44 , NVIDIA Corporation

 

Total time spent in DPCs (%)                          0.451373

 

DPC count (execution time <250 µs):                   3582912

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

DPC count (execution time 500-999 µs):                7156

DPC count (execution time 1000-1999 µs):              1

DPC count (execution time 2000-3999 µs):              1

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

 

When dwm is maxing out the system is very unresponsive (even typing is jerky) and it's driving me mad. I hate WIn 8 anyway and am half thinking of downgrading to Win 7 but I can't afford the time to do so.

 

Help!

 

Andy