DPC Latency will destroy the AVAST'S reputation ?

[bong2x]

hello my friend!! did you check the service host?

i try to figure out if it is the same in mine

but see the result in mine, i will try it again if it give high peak.

friend i figure out that also give me a high peak reading if my cpu is over heat.

the cpu fan running, the electromagnetic flux it causes interference also

i don't understand the fan is mounted at the heat zinc why the EMF give interference

if you don't mind try to replace your processor fan a new one.

Regards!!!

[NON]

hello my friend!! did you check the service host?

i try to figure out if it is the same in mine

but see the result in mine, i will try it again if it give high peak.

friend i figure out that also give me a high peak reading if my cpu is over heat.

the cpu fan running, the electromagnetic flux it causes interference also

i don't understand the fan is mounted at the heat zinc why the EMF give interference

if you don't mind try to replace your processor fan a new one.

Regards!!!

I found some articles saying cleaning PC's cooling system (CPU Fan, heatsink, vent...) solves high DPC Latency, so it's worthy to try it.

If CPU got over heat, CPU downs its clock to protect itself, and this causes performance decline... so normally DPCs don't consume much CPU time, but with low CPU performance it consumes much CPU time.
I've forgotten Cako runs his PC all day (moreover with full scan!), so it's very likely to happen this symptom... what a fool I am! :'(

Anyway, Happy Easter to all! If your problem is solved, it must be a present from the sky.

Edit:
I have some red bars... now I run my PC with Battery-mode (CPU clock downs to 800MHz).

Edit2:
I now remember this problem doesn't appear with .396... so it seems this is not the reason.

[Cako]

hi guys.
thanks for the tip,
but on my PC when the processor becomes very hot it restarts my pc.
To  fix it i just clean the fan and the problem is fixed.
I check the fan and the processor end its clean end working properly here.
I think NON is right.
fix this problem must be a present from the sky.
but I'll keep trying.
so far I dont have much news.

[Cako]

fixed problem with the mouse.
I uninstall a PC game called SWAT 4 to fix it.
and i cleaned the windows registry.
the mouse stopped jumping from the one side to other side on the screen.
I think somehow avast and the game had a conflict because when I disable all the shields from avast also stopped the problem.

DPC latency is not fixed yet.
I updated to version eMule 0.50a end the problem continues.
I'll wait for the next version of avast free (final), I will update and expect some results.
but I dont have hope in the next version of avast
i dont think this will go help end alleviate the problem.
I hope I'm wrong.
I will keep trying find the solution to be able to use the P2P shield again ..

[NON]

fixed problem with the mouse.
I uninstall a PC game called SWAT 4 to fix it.
and i cleaned the windows registry.
the mouse stopped jumping from the one side to other side on the screen.
I think somehow avast and the game had a conflict because when I disable all the shields from avast also stopped the problem.

Hi Cako,
I'm glad to hear one of your problems were fixed. I hope you are not too tired.

DPC latency is not fixed yet.
I updated to version eMule 0.50a end the problem continues.
I'll wait for the next version of avast free (final), I will update and expect some results.
but I dont have hope in the next version of avast
i dont think this will go help end alleviate the problem.
I hope I'm wrong.
I keep trying to find the solution to be able to use the P2P shield ..

Latest build contains some fixes about winsock, which is related to network. I hope this has some effects on your problem.
But, I feel that the circumstances of your problem is now changing... before you posted an terrible DPC Latency after full-scan. Full-scan is not related to P2P shield, so it seems the culprit is not network-related but another stuff.

I'll suggest these. I don't know whether you already did these or not, but just in case:
- Does disabling avast heuristic in P2P shield change your issue?
- Hard HDD access with/without avast show some changes? (related to full-scan issue)
- Try to clean unused / remained security-software device driver.
Device manager -> "Show" menu? -> Enable "Show unshowed device"? -> Un Plug & Play driver
I think there are many remains in this category, so delete them. Please be careful not to delete system driver (driver vender's name will help distinction).
Sorry for "?" marks... I don't know how these menus called in English


And here is my situation:
Update graphic driver: No major effect
Install vendor's mouse driver/utility: Module "USBPORT.sys" disappear and "Unknown" appear in xperf
Uncheck "increase mouse accuracy": A bit decline DPC Latency caused by USBPORT.sys
Change audio codec (Windows default -> ffdshow Audio Codec): Sound shuttering decreases dramatically

[Cako]

fixed problem with the mouse.
I uninstall a PC game called SWAT 4 to fix it.
and i cleaned the windows registry.
the mouse stopped jumping from the one side to other side on the screen.
I think somehow avast and the game had a conflict because when I disable all the shields from avast also stopped the problem.

Hi Cako,
I'm glad to hear one of your problems were fixed. I hope you are not too tired.

DPC latency is not fixed yet.
I updated to version eMule 0.50a end the problem continues.
I'll wait for the next version of avast free (final), I will update and expect some results.
but I dont have hope in the next version of avast
i dont think this will go help end alleviate the problem.
I hope I'm wrong.
I keep trying to find the solution to be able to use the P2P shield ..

Latest build contains some fixes about winsock, which is related to network. I hope this has some effects on your problem.
But, I feel that the circumstances of your problem is now changing... before you posted an terrible DPC Latency after full-scan. Full-scan is not related to P2P shield, so it seems the culprit is not network-related but another stuff.

I'll suggest these. I don't know whether you already did these or not, but just in case:
- Does disabling avast heuristic in P2P shield change your issue?
- Hard HDD access with/without avast show some changes? (related to full-scan issue)
- Try to clean unused / remained security-software device driver.
Device manager -> "Show" menu? -> Enable "Show unshowed device"? -> Un Plug & Play driver
I think there are many remains in this category, so delete them. Please be careful not to delete system driver (driver vender's name will help distinction).
Sorry for "?" marks... I don't know how these menus called in English


And here is my situation:
Update graphic driver: No major effect
Install vendor's mouse driver/utility: Module "USBPORT.sys" disappear and "Unknown" appear in xperf
Uncheck "increase mouse accuracy": A bit decline DPC Latency caused by USBPORT.sys
Change audio codec (Windows default -> ffdshow Audio Codec): Sound shuttering decreases dramatically

Hi NON 
my english is not very good, but I think it was possible to understand,your problem is almost solved,I think.
I am very happy to know.

- Does disabling avast heuristic in P2P shield change your issue?

I had already done it, the problem it only happens when files are scanned emule.

- Hard HDD access with/without avast show some changes? (related to full-scan issue)
- Try to clean unused / remained security-software device driver.
Device manager -> "Show" menu? -> Enable "Show unshowed device"? -> Un Plug & Play driver
I think there are many remains in this category, so delete them. Please be careful not to delete system driver (driver vender's name will help distinction).
Sorry for "?" marks... I don't know how these menus called in English

I dont did this,but i will.
I will put the result later.
thanks.....

[Cako]

I will install the 499 version right now, but I think it should not change much ..
I will install and test......

[Moba]

I can confirm the issue after running the DPC tool on my X60 Thinkpad with Windows 7 Ultimate (32 bit). Removing Avast solved the issue.

However, "destroy Avast's reputation" might be a bit harsh; I'm sure the Avast team will look in to it. Lots of software have bugs and with all the hardware/software combinations possible, it's impossible for any dev team to produce 100% bug free software.

[Vlk]

I can confirm the issue after running the DPC tool on my X60 Thinkpad with Windows 7 Ultimate (32 bit). Removing Avast solved the issue.

However, "destroy Avast's reputation" might be a bit harsh; I'm sure the Avast team will look in to it. Lots of software have bugs and with all the hardware/software combinations possible, it's impossible for any dev team to produce 100% bug free software.

The point of this lengthy thread (or our contributions so far) is that we have been "looking into" this issue for like half a year now. The problem is not reproducible on our test systems, which makes me think it has to be a conflict with another program / driver.

However, about half of our test systems exhibits the behavior no matter if avast is installed or not - just a clean install of Windows plus all hardware drivers are enough to have DPC latencies go haywire every now and than.

Performance tuning is something we spend significant time on; the DPC latency problem, however, is so subtle and influenced by so many external factors that it really needs to be analyzed on individual basis, case by case. This is also why the extensive documentation accompanying the DPC test tool doesn't tell you how to solve the problem - there's no simple here.


Now, if the problem is reproducible on your system (win7), it would be useful if you could do the xperf.exe experiment for us, as described above. Is that something you could do?

Thanks,
Vlk

[Cako]

I am conscious of the difficulty to fix this problem with the DPC latency.
I spent many hours researching and trying to do tests on my PC to fix this.
but I never heard about DPC latency before installing avast 5.
anyway, i dont spend my time, knowledge about anything is very good.
I am not a developer, I dont know how to programming a software, but I am persistent.
I dont know much about PHP but when I needed, learn and create my own PHP mail.
I'm not very smart if I can anyone can.
but drivers are not PHP, and in my country it is illegal to modify software without authorization.
I dont want trouble with the law.
I can not install the WDK end modify the drivers one by one.
so I just do what I can do.
look:
AVAST free 5.0.499 after 40 minutes using P2P shield to scan emule files,no DPC problems:

[NON]

Hi Cako,

Hi NON 
my english is not very good, but I think it was possible to understand,your problem is almost solved,I think.
I am very happy to know.

Changing audio codec is only an allopathy, not a permanent solution... but I don't have any complaint with this anyway.
Now I think my (relatively high ) DPC Latency is caused by Comodo Firewall... they had same issue before, and it can happen on my PC too.


And Mova, welcome to the forums. If you have some time to analysis your DPC issue, please do it; it can help identify what happens on your / our PCs.
Here is usage of xperf again:
Edit: You can download Windows Performance Analysis Toolkit from next post by vlk.

To try and help identify the cause of this phenomena, perhaps you would care to delve a little deeper into your systems. The DPC latency checker, whilst being a helpfulutility, sadly lacks any useful information. To get more detailed information, please use the following guide and report your findings:

2. Download Windows Symbols Package for your OS (you may or may not need them) http://www.microsoft.com/whdc/devtools/debugging/symbolpkg.mspx#d

3. Install the Windows Performance Analysis Tools (you might wish to change the install path to something easy to navigate to)

4. Open a command prompt (elevated if necessary) and navigate to the xperf folder the default is "C:\Program Files\Microsoft Windows Performance Toolkit"

5. For the sake of simplicity type:

 xperf -on DiagEasy and press return.

This will begin the trace. I suggest letting it run for several minutes to ensure you capture the details required.

6. After a time has passed type :

xperf -d trace.etl and press return.

This will stop the trace.

7. Type:

xperf trace.etl and press return.

This will display the results. We could have collected more specific data but using the DiagEasy switch is good enough for our purposes.

8. Scroll down to the section headed DPC CPU Usage.

9. Select a nice big spike, this corresponds to the spikes you will have observed in DPC latency checker. Select the spike and right click. From the menu select Summary Table. This will open a new window with details regarding drivers. The higher the value the more problematical the driver.

10. Report your findings here.

Best wishes,
NON

[Vlk]

BTW the Windows Performance Analysis Tools can easily downloaded from here:
32-bit http://public.avast.com/~vlk/wpt/wpt_x86.msi
64-bit: http://public.avast.com/~vlk/wpt/wpt_x64.msi

Getting them via the SDK is a pain.

Thanks
Vlk

[NON]

BTW the Windows Performance Analysis Tools can easily downloaded from here:
32-bit http://public.avast.com/~vlk/wpt/wpt_x86.msi
64-bit: http://public.avast.com/~vlk/wpt/wpt_x64.msi

Getting them via the SDK is a pain.

Many thanks, vlk

[snarky]

I installed AIS 5.0.462 yesterday.  I'm also using uTorrent 2.0 and WinXP Pro SP3 (32-bit).

I have noticed higher-than-usual DPC usage on my system.  I run Process Explorer constantly in the tray, and at any given time, DPC is using 15-30%.  I know for certain that this is not typical for my system, since I have always checked Process Explorer very frequently.

So far, there has been one time (that I've noticed, at least) that DPC usage was 80-100%.

I do have uTorrent checked in the P2P shield.  I know it's not checked by default.  I was experimenting.

When I stop the P2P shield, the DPC usage remains 15-30% continually.  I have not tried disabling the P2P shield and rebooting.

I'll probably simply disable and/or remove the P2P shield and hope that fixes the problem.

[Cako]

I installed AIS 5.0.462 yesterday.  I'm also using uTorrent 2.0 and WinXP Pro SP3 (32-bit).

I have noticed higher-than-usual DPC usage on my system.  I run Process Explorer constantly in the tray, and at any given time, DPC is using 15-30%.  I know for certain that this is not typical for my system, since I have always checked Process Explorer very frequently.

So far, there has been one time (that I've noticed, at least) that DPC usage was 80-100%.

I do have uTorrent checked in the P2P shield.  I know it's not checked by default.  I was experimenting.

When I stop the P2P shield, the DPC usage remains 15-30% continually.  I have not tried disabling the P2P shield and rebooting.

I'll probably simply disable and/or remove the P2P shield and hope that fixes the problem.

if you want a temporary solution uncheck the utorrent in the P2P shield's option.
but before doing that use the Windows Performance Analysis Tools if you use the windows vista/7 .
You can download here (links from vlk) :
32-bit http://public.avast.com/~vlk/wpt/wpt_x86.msi
64-bit: http://public.avast.com/~vlk/wpt/wpt_x64.msi

if you use the windows XP use the rattv3 ,this it is a tool for auditing the execution times of interrupt service routines (ISRs), deferred procedure calls  (DPCs)
You can download here:
http://www.microsoft.com/whdc/DevTools/tools/RATT.mspx

go to C:\WINDOWS\system32\LogFiles\RATTV3 end open the logfile with wordpad end save to fix the words.
Put the log here.

Changing audio codec is only an allopathy, not a permanent solution... but I don't have any complaint with this anyway. Smiley
Now I think my (relatively high Roll Eyes) DPC Latency is caused by Comodo Firewall... they had same issue before, and it can happen on my PC too.

NON, we will continue to search for a permanent solution.

look:
AVAST free 5.0.499 after 4:29 minutes using P2P shield to scan emule files,the DPC problems again:
well, if they cant simulate this problem, they cant fix.. :'(