Windows 7: Network usage causes high DPC Latency

I tried an Intel Network card (instead of the onboard Realtek) and it did not help...

:/

I have 2 PCs with Windows 7 x64 . One has an Intel MB DH55HC with i7 860 CPU and an onboard Intel NIC . I get the high DPC latency, and tracked it down to NDIS.sys. I added a Realteck NIC, and for a few days it worked fine. But now this too has the high DPC when downloading, though not to the extent of the INtel NIC.
The second PC has an MSI board with nVidia chipset and NIC and core 2 duo CPU - has no problems at all with DPCs.
I hope MS updates NDIS.sys to solve this problem.

I can confirm I am having issues with this right now.

I have been having issues with having to reboot to gain performance back.
Upon researching I found out about DPC latency and downloaded the app.

After seeing spikes upwards of 100,000 uS (YES actually that high), I knew this had to be the reason I was needing to reboot.

After messing around and disabling different drivers, I found it to be my Atheros AR8121/AR8113/AR8114 PCI-E Ethernet controller. As soon as I disable it, all latency peaks subside.

So, further experimenting, I found that I could reboot my laptop, and latency would be in the green zone. Within two minutes of starting uTorrent, blam, red spikes that progressively get bigger overtime.

So, I went to uTorrent forums and found this is a common issue, more so since more people are going to Win 7 OS.

I decided to download Vuze and install it. I then rebooted my PC, and started Vuze. About 5 minutes later, I started getting spikes.......
But much different. These spikes would come in equal intervals.....every 10 or so seconds and they never got higher than 5000 uS.
I even tried downloading the same three files with both bit torrent clients for a consistent test.

I could see there was clearly a difference between the two bit torrent clients.
If I have to choose, I'll take Vuze's symptoms over uTorrent's. The latency I see with Vuze doesn't seem to affect my PC stability, but it does with uTorrent, especially overnight.

I am an avid user of PS3 Media Server and I have noticed that this latency affects my streaming sometimes as well.

While using Vuze seems to be better than uTorrent, the trade-off is that Vuze uses much more CPU power than uTorrent. I hope this issue can be solved (whatever the root cause is), as I like to be able to download material at the same time I am serving other media over my network. As I sometimes need to transcode the material, the lower CPU usage from uTorrent is appealing vs Vuze's CPU usage, but I have HIGH DPC latency with uTorrent.

I have tried the latest Atheros drivers up to version 1.0.0.49 which seemed to help a little, but as soon as I get high network traffic, specifically internet traffic, then the problem creeps back.
LAN traffic (media serving) doesn't go nearly as crazy as downloading material over the internet.

Still waiting for Intel support to solve this. In the mean time I found a way to restore normal DPC latency without rebooting: Go to Services and restart Base Filtering Engine. After this you need to restart Windows firewall from the Action Center in the systray .

Eross! You are my hero! This is such an awesome workaround!

For anyone else: I created a batch file (restartservices.bat) to restart the service:

net stop "Base Filtering Engine"
net start "Base Filtering Engine"

(remember to right click the batch and click "run as administrator")

Thanks for the batch file. To automatically answer Yes to the question in the batch file write it like this:
net stop "Base Filtering Engine" /Yes
net start "Base Filtering Engine"

AHHHGHGHGHHGHHHGHGHG!!!!

I F---ing solved it !!!!

I made an account here just for posting this! I looked at this problem for 4 months and tried EVERYTHING!

All my symptoms are the same.. network traffic causes spikes. audio was jumping and popping. forget about HD video. every time I connected or disconnected to a network the spikes peaked at 33ms and stayed there for 5 minutes! you couldn't touch the computer. once every few hours when network traffic was very high (downloading at max speed) it froze completely and a reset was required. I tried every combination of driver and bios versions out there.
first of all there's this program
Resplendence Software - LatencyMon: DPC, ISR and pagefault execution monitor
it can tell you what driver exactly is causing the spikes
just run it - press play and go to drivers. there click on the highest execution to sort by it.
I saw that the major culprit was dxgkrnl.sys and ACPI.sys and nvlddmkm.sys and even USBPORT.sys. All of these had execution times higher than 1.0 ms. It was exactly the same as the latencies in the DPC latency checker.

apparently all (except the USBPORT.sys) are related to nvidia drivers. Specifically they are related to a feature that's called Powermizer. I found a tool to disable it easily:
Powermizer Switch.rar - File Shared from Box.net - Free Online File Storage
just run it click powermizer off and reboot!!! It solved everything for me! even the USBPORT.sys is under 0.4 constant now! (before they were all over 19.0ms and 18,000+ in dpc checker) check out my DPC! WOOOHOO! thank you everyone!!

You sound very enthusiastic.
I downloaded the LatencyMon and had different results. It says that these drivers
tcpip.sys (TCP/IP Driver by Microsoft),
nvlddmkm.sys (NVIDIA Windows Kernal Mode Driver),
ntoskrnl.exe (Windows)
netbt.sys (MBT Transport Driver)m
dxgkrnl (DirectX, Microsoft)
ndis.sys (NDIS driver, Microsoft)
have the highest execution time, where the maximum is 0.76 ms.
So, while NVIDIA has only one driver in the top, Microsoft is the main knave.
Also, I observed that the problem is related to network (mainly ndis), and has not to do anything with graphics.

That's why I decided to not download an exe from a fileshare server and execute something from an author I never heard of before without knowing what (else) this software does.

Are you using a laptop PC? Because Powermizer is a feature only for battery operated PCs:
NVIDIA PowerMizer Technology

Ofcourse I was enthusiastic!! I told you I had this problem for about 4 months and I tried everything to solve it. I totally understand you not wanting to download this thing (now I'm a little worried because I myself don't have a clue who made this). So I looked up and here is the same solution without any program to download just tweak some reg keys:


\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Video\{**a series of numbers that are different**}\0000\PerfLevelSrc




Step 3- What we need to do once you found PerfLevelSrc is edit it by double clickin and changing the value data from 3333 to 3322. Click ok.





Step 4- Find "PowerMizerEnable" which is probably 5 ways down from "PerfLevelSrc". When you find it double click on PowerMizerEnable and change the value data from 1 to 0.



This will disable Powermizer

Step 5 - Find PowermizerLevel and change the value to 1

Step 6- Find PowermizerLevelAC and change value to 1



this one i didnt try because the program worked for me but I guess its exactly the same. hope this works for you. But in any case, if nothing is going over 0.8ms or so in your case, this is a very good latency and its weird that you are still getting spikes in DPC latency checker. Do you?



yea, I have MSI GX630 laptop with AMD athlon X2 QL-62, nvidia gforce 9600GT, 7.1 onboard realtek audio.
Maybe my problem was not the same as yours but I think that trying to disable the powermizer option can do no harm even if you have a desktop.

I should add a few details though on what it was like before the fix:
I never experienced any problem with win XP on the same machine (I have both windows installed on separate drives)
Also, when I disabled the network , WLAN and bluetooth devices everything calmed down to the green - but it took some serious red zone spikes before it did and after restarting the devices you couldn't do anything for a few minutes (spikes were constantly in the 30-60 thousands...) to the point where sometimes the computer froze entirely and a reset was required. I also should note that when I installed a fresh Windows 7 (one of the first things I tried) before I installed ANYTHING else, the latency wasn't that bad - mostly yellow and only sometimes red, but after the sound drivers and especially the network and WLAN drivers were installed everything got crazy just like before.


Hope this helps I created an account & posted here just for this solution!