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MagicAndre1981

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

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vfwh    0

this is a really strange issue with your headset. Ok, post us what you found out later :)

Well, it's a hell of a weird story, but it's, er, "fixed", so to speak.

Basically, if I ease out the headset jack just a fraction, then it works... There's some issue also about the fact that trrs (mic and audio out in the same jack) is not implemented properly in Bootcamp/Win7. It's threrefore probably related, as the trrs depends on finer position of the connector in the jack, I guess. Or something.

You can go here to find out more details about that story and how broad of a user base that issue affects, with Apple obviously not giving a rat's a**:

http://discussions.apple.com/thread.jspa?messageID=11200699

Cheers.

V.

P.S.: I did of course try several driver versions for the internal Cirrus Logic and so on, to no avail.

Edited by vfwh

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sounds    0

Ididnt think it woudl do anything if I uninstalled the Firestudio driver, but it did. and it when I ran the W7 health report it said nothing of high interrupt rate. So i guess i will let presonus know. thanks Andre.

I have a high interrupt rate. it does it even if my firestudio is not plugged in.

but the drivers are installed! What happens if you remove the drivers? If the issue gone?

Edited by sounds

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Ididnt think it woudl do anything if I uninstalled the Firestudio driver, but it did. and it when I ran the W7 health report it said nothing of high interrupt rate. So i guess i will let presonus know. thanks Andre.

ok, so contact the support of PreSonus.

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Hi, the idle process is nothing you should worry about. The intelppm.sys brings the power saving features of your CPU to Windows.

Extend the "System" node please and post the new picture!

regards

André

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VultureX    0

Hello,

thank you for this tutorial :)

While analysing my laptop* I found 2 things.

This is with my WLAN enabled. There are 2 bands with high CPU usage to see. During that time I was downloading and uploading with about 1.3MB/s respectively.

There are also other peeks to be noticed. I will come back to those later.

WLANDPC.jpg

As you can see, the main culprit is the ndis.sys driver, which indicates bad WLAN drivers. Is there something I can do about this, besides updating the drivers? I can't find any new drivers on the net. I can't find ANY firmware updates on the net. :(

The latest drivers I can find are:

http://www.atheros.cz/download.php?atheros=AR9285&system=3

which have version number 7.7.0.331, which are in fact older than the Windows Update drivers which have version number 8.0.0.238

I've found some drivers on MSI's site and I've tried multiple versions, but it makes no difference for the high DPC latencies.

WLANanalyzed.jpg

Now the trace with WLAN disabled:

NoWLANDPC.jpg

NoWLAN.jpg

There's just peeks to be seen. These are the same peeks you saw after the downloading/uploading in the previous images. These peeks occur every 15 seconds and are caused by:

NoWLANanalyzed.jpg

ACPI.sys. This does not change with a (sort of) clean boot.

'Sort of' clean boot? Well, the norton internet security service does not allow itself to be disabled. When I deselect it and click apply it just becomes selected automatically again. Even in safe mode...

*

MSI CS620:

Interl Core i3-330M

ATi Radeon HD5470

4 GB DDR3

Win7 32 bit

Wireless Network Adapter: Atheros AR9285

Edited by VultureX

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VultureX    0

Why shouldn't I worry about the WLAN?

When I'm downloading at 2MB/s, CPU usage exceeds 20%. That means 1 thread is near fully loaded (dual core CPU; 4 threads)!

With the WLAN card enabled I experience random >4000 microseconds DPC latency spikes. This can well be the cause of input lag (intermittent pauses while typing) that I'm experiencing.

I can confirm I have the latest BIOS and chipset drivers.

Edited by VultureX

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I think it may be caused by the PowerSaving feature of your mobile Intel i3 CPU. Which powerplan do you use? Try changing to high performance and disable all power saving features. Does it help? Or do you still have spikes from the ACPI.sys driver?

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