DPC Latency will destroy the AVAST'S reputation ?

[YoKenny]

Your DPC latency is still pretty high, specially the peak.
Try to check it with LatencyMon

See

NOTE: Because LatencyMon relies on ETW tracing it does not support any version or edition of Windows XP or Windows 2003 Server.

http://www.resplendence.com/latencymon_os

What does it have to do with XP and 2003???
Your signature shows that your on 7.....
My point is that Avast's NDIS driver conflicts with some NIC drivers not the other way.

I have both systems!
I have no problem on my XP Pro system but I see a problem on my Windows 7 system with DPC Latency Checker but it performs perfectly. 

[JoeB]

What does it have to do with XP and 2003???
Your signature shows that your on 7.....
My point is that Avast's NDIS driver conflicts with some NIC drivers not the other way.

I have both systems!
I have no problem on my XP Pro system but I see a problem on my Windows 7 system with DPC Latency Checker but it performs perfectly. 
[/quote]
There is an impact caused by dpc latency spikes in some multiplayer games, which is mainly noticeable by random stuttering when fps is max and network latency is very low.
First thought would be that the issue is server side, but that is not the case for this instance.

I'm looking forward to check out the coming major version of the Avast Internet Security suite though, should be a chance for that it performs much better on Windows 7.

[Nesivos]

Found this thread on the Windows 7 Forum

Network usage causes high DPC Latency

Looks like the problem might me related to a NIC card driver and Windows

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!!

http://www.sevenforums.com/network-sharing/52935-network-usage-causes-high-dpc-latency-4.html

[silviucc]

@Nesiovs That post is so old it should have grown a beard by now. Anyway, my DPC latencies went away after I unsintalled the firewall module from AIS. And yeah, they were caused by massive usage of the net connection. It also manifested with an Intel PCIe x1 NIC.

Powermizer causes DPC spikes on some machine, but what we were talking about here was constant high DPC latency while downloading something via torrents with the AIS firewall driver still loaded.

[Cako]

@Nesiovs That post is so old it should have grown a beard by now. Anyway, my DPC latencies went away after I unsintalled the firewall module from AIS. And yeah, they were caused by massive usage of the net connection. It also manifested with an Intel PCIe x1 NIC.

Powermizer causes DPC spikes on some machine, but what we were talking about here was constant high DPC latency while downloading something via torrents with the AIS firewall driver still loaded.

its old but is working and help other people with the same problem.....

[lukor]

Hi guys, I can confirm some DPC issues with AIS Firewall in the current version with massive connection counts. We are currently analyzing the problem and trying to come up with some fix, hopefully for the upcoming version 6.

[YoKenny]

Hi guys, I can confirm some DPC issues with AIS Firewall in the current version with massive connection counts. We are currently analyzing the problem and trying to come up with some fix, hopefully for the upcoming version 6.

Will it be fixed in avast! Free

This pic is from my Windows 7 system.

[Nesivos]

Hi guys, I can confirm some DPC issues with AIS Firewall in the current version with massive connection counts. We are currently analyzing the problem and trying to come up with some fix, hopefully for the upcoming version 6.

Will it be fixed in avast! Free

This pic is from my Windows 7 system.

From what you have put in your signature I would suggest considering adding to the 1.5GB of memory.  My guess is that adding additional memory will significantly reduce your DPC Latency.

[YoKenny]

From what you have put in your signature I would suggest considering adding to the 1.5GB of memory.  My guess is that adding additional memory will significantly reduce your DPC Latency.

As usual you have no clue what I am talking about as my Windows 7 system already has 4GB RAM 

[Nesivos]

From what you have put in your signature I would suggest considering adding to the 1.5GB of memory.  My guess is that adding additional memory will significantly reduce your DPC Latency.

As usual you have no clue what I am talking about as my Windows 7 system already has 4GB RAM 

I read the wrong RAM number.

I still don't think that the DPC Latency problems that people are experiencing has to do with AIS.  I don't know about Avast AV because I don't use it.

I quite thoroughly tested the DPC Latency on my computer and only noticed a single bar spike over 500us.*** The DPC checker was open by itself on my second monitor and easily visible the whole time so I didn't miss anything.  The checking took place with Firefox 4.0B10 having about eight tabs open, running 20 addons, downloading Torrents, running a AIS scan and playing a YouTube streaming video all at the same time.

*** In addition to one program, SystemRestoreCreation generating a single red bar spike when it completed. 
   

[YoKenny]

I don't know about Avast AV because I don't use it.

If you do not use avast! AV then why are you here offering advice

[DavidR]

Hi guys, I can confirm some DPC issues with AIS Firewall in the current version with massive connection counts. We are currently analyzing the problem and trying to come up with some fix, hopefully for the upcoming version 6.

Will it be fixed in avast! Free
<snip>

Well if you are using the free version and the DCP issue is with the AIS version then I doubt it will fix that, I have no problem on my XP Pro system with avast free 5.1.889. The small spike was after restarting it all the previous columns were Green.

My little win7 netbook (Atom Dual core, 2GB DDR3 RAM, WiFi connection to router) with avast free 6.0.945 beta does have some issues, which is strange as it is very new and has no external devices hooked up so no device drivers required for them.

[YoKenny]

Well if you are using the free version and the DCP issue is with the AIS version then I doubt it will fix that, I have no problem on my XP Pro system with avast free 5.1.889. The small spike was after restarting it all the previous columns were Green.

My little win7 netbook (Atom Dual core, 2GB DDR3 RAM, WiFi connection to router) with avast free 6.0.945 beta does have some issues, which is strange as it is very new and has no external devices hooked up so no device drivers required for them.

I am using avast! Free on the Windows 7 system and avast! Pro on XP Pro.
It makes no difference on Windows 7 if I use avast! V5.1.89 or the new beta but I am going to wait for avast! V6 official release on my XP Pro system as having to do a clean install of the beta is a bit of  a pain. 

[DavidR]

Well neither of those have the AIS Firewall in the current version as it isn't AIS, so I don't believe that avast 6 for free/pro will do anything for non-AIS related firewall issues. As you can see my win7 netbook has some latency but not as bad as yours.

So I would suggest following the notes in the bottom window of your image. Use Device Manager and check W-LAN adapters, modems, internal sound devices, USB Host controllers, etc.

There are tools to check your drivers and see if there are any updates available.

[lukor]

Hi guys, I can confirm some DPC issues with AIS Firewall in the current version with massive connection counts. We are currently analyzing the problem and trying to come up with some fix, hopefully for the upcoming version 6.

Will it be fixed in avast! Free

This pic is from my Windows 7 system.

The problem I was talking about is specific to firewall and hence it does not exhibit any behavior in free version and the fix will not help there. DPC is not something bad in general. Many things in the system are going to happen on the DPC level, if you like it or not. For example most of the network related code is executed on DPC. And this is perfectly ok, what is not ok is when some piece of code is blocking others for too long. You might want to have it done quickly but sometimes it might be better to wait a while and let others to do their work for a while, this makes the system respond smoothly while performing other tasks in the background. Having some spikes of red in one program does not mean anything, if your system does not respond, your mouse is not smooth, your sound is choppy - that's a problem.

Lukas