# [SOLVED] Severe DPC Latency Problem with Network Adapter (Windows 7 64bit)



## mattcaps (Mar 2, 2010)

I'm having a major issue with DPC Latency on my Windows 7 (64bit) machine.

After experiencing audio and video drop-outs recently, I downloaded DPC Latency Checker v1.2 and found out that the problem is tied to my network adapter. The latency spikes well into 16000 (which is insanely high) when I open a new browser or navigate to a new page in any browser.

If I disable the network adapter and open a new browser, the latency is within normal range.

I've updated to the current network drivers directly from Intel, and I even looked into the IRQ priorities in my registry. There were no IRQ priority conflicts and I changed the network adapter priority to 3. Didn't work.

I've also scanned my machine with Norton Antivirus (and I've had it running since I installed Windows 7).

Tried to update my Bios but the installer wouldn't run properly.

What is the issue here? Maybe my network adapter hardware is broken? 


Hardware:

Mobo: Intel D975XBX2
Network Adapter: Intel PRO/1000 PL Network Connection
Processor: Intel Core2 6600 (2.4Ghz)
BIOS Version: Bx97520J.86A.2634.2007.0216.1057
Graphics: NVIDIA GeForce 8800 GTS
HD: Dual ST3320620 ATA (300gb each)


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## jcgriff2 (Sep 30, 2007)

*Re: Severe DPC Latency Problem with Network Adapter (Windows 7 64bit)*

Hi - 

What happens when you use Internet in SAFEMODE w/ Networking?

I know that legacy driver vga.sys will load in SAFEMODE in place of video adapter driver and no sound, but am interested in the results since you believe NIC responsible.

Regards.. .

jcgriff2

.


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## mattcaps (Mar 2, 2010)

*Re: Severe DPC Latency Problem with Network Adapter (Windows 7 64bit)*

I also tried turning off some possible Services culprits, one at a time, and it didn't help much:

http://www.blackviper.com/Windows_7/servicecfg.htm


Can anybody help with this problem?


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## mattcaps (Mar 2, 2010)

*Re: Severe DPC Latency Problem with Network Adapter (Windows 7 64bit)*

jcgriff2:

I started in safe mode with networking.

Unfortunately I can't run the DPC Latency Checker in safe mode, so I can't tell if the latency spikes are still occurring. 

It seemed like the browsers were still slowish though... so the spikes might still be happening.

Any other ideas??


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## jcgriff2 (Sep 30, 2007)

*Re: Severe DPC Latency Problem with Network Adapter (Windows 7 64bit)*

What about apps that utilize the Internet - self-updating, behind-the-scenes, etc... ?

What does the Resource Monitor have to say?
START | *perfmon /res* - click on "Network" tab 

What's going on in there?

When a spike hits, run a system health report (force a spike - a good one !!!)
START | *perfmon /report* | save as HTML file

Also, throw in an msinfo32 NFO file, please. . .
START | *msinfo32* | save w/ default NFO file ext

Zip them up & attach.

Regards. . .

jcgriff2

.


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## mattcaps (Mar 2, 2010)

*Re: Severe DPC Latency Problem with Network Adapter (Windows 7 64bit)*

I've attached the files you requested along with a screen shot of the resource monitor.

There are at least two huge latency spikes in the report.


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## jcgriff2 (Sep 30, 2007)

*Re: Severe DPC Latency Problem with Network Adapter (Windows 7 64bit)*

Firefox is somwhat active.... same screen in Resource Monitor, but check the box next to Firefox, then click the bar below "Network Activity" - it should give you more info. Same with the TCP and Listening Ports.

This is an intersting looking system service - 

```
[FONT=Lucida Console]
1262562541	.1262562541	
	c:\program files (x86)\1262562541\[COLOR=Red]mattcaps1262562541l.exe[/COLOR]	Normal	LocalSystem	0[/FONT]
```
Any ideas?

This without much doubt is a major problem - 

```
[FONT=Lucida Console]\Programs\LimeWire
[/FONT]
```

Look at the network activity for Firefox. How many screens/ tabs did you have open? Note PID = 4328




The "Working Set" size for Firefox = 320 MB. Note PID = 4328 - same as above -



`

To test - I opened up a single IE8 screen, then opened 15 tabs within that same IE8 screen. Total Working Set memory = 217 MB

To start - ditch LimeWire.

Regards. . .

jcgriff2

.


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## mattcaps (Mar 2, 2010)

*Re: Severe DPC Latency Problem with Network Adapter (Windows 7 64bit)*

I only had a couple tabs open in Firefox. The problem also happens when going to any single page... and it happens with chrome and safari too...

I uninstalled Limewire and I also removed that system service.

The DPC spikes have not been eliminated.

Do you think I should just to a clean install of Windows?


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## jcgriff2 (Sep 30, 2007)

*Re: Severe DPC Latency Problem with Network Adapter (Windows 7 64bit)*

What about IE8?

Try the browsers in SAFEMODE w/ Networking.

A re-install would be a good idea at this time.

Regards. . .

jcgriff2

.


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## mattcaps (Mar 2, 2010)

*Re: Severe DPC Latency Problem with Network Adapter (Windows 7 64bit)*

The spikes are still occurring, even with IE8 or any other browser in safe mode w/ networking.

I think I'm going to try a clean install, which is a huge pain, but hopefully the issue will be solved.


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## mattcaps (Mar 2, 2010)

*Re: Severe DPC Latency Problem with Network Adapter (Windows 7 64bit)*

I think I finally found the source of the problem. 

I just did a complete Windows reinstall, and only installed new network adapters and Norton Antivirus 2010. To my amazement, the spikes were still occurring. I uninstalled Norton, and the spikes went away.

I called Norton and they gave me a full refund of my 1-year subscription.

I wish I could have known that Norton Antivirus was the source of this before I formatted my drive!


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## jcgriff2 (Sep 30, 2007)

*Re: Severe DPC Latency Problem with Network Adapter (Windows 7 64bit)*

I did note the Norton before, but did not mention because it was not NIS or N360. Was it in fact Norton or Symantec Anti-virus and not the Internet Security product? One thing I do know, is all of those products feel the need to "phone home" every 15 minutes.

Apologies for not mentioning it before your re-install.

Regards. . .

jcgriff2

.


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## mattcaps (Mar 2, 2010)

No worries. I thought the issue was the NIS because when I disabled the NIS the problem went away. But in actuality Norton was doing something crazy every time I navigated around the web.

I actually solved a couple other bios issues due to reinstalling windows anyways... so all is good.

Thanks for the help.


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## jcgriff2 (Sep 30, 2007)

Glad things worked out.

Thank you so much for posting back with your found solution. Much appreciated!

Regards. . .

jcgriff2

.


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