CPU Idling at 20% from System Interrupts

I've gone through at least a dozen hoops to try and fix this, first here are specs

Intel ExtremeEdition 955 Dual-Core (Pentium D) with Hyper Threading, 3.46Ghz (not overclocking)

nVidia GeForce 9600 GT

FoxConn 975X7AB

2Gb DDR2 RAM

Ok, here's the problem. Fresh install of Win7 (64-bit), open up Resource Monitor and see System Interrupts taking 16-20% cpu. (Not sure if this is important, but it's 75-85% on 1 core out of 4.) Things I've tried:

-Updating drivers for EVERYTHING

-All IDE devices are running in DMA mode

-some people had a problem with a Realtek audio driver for high definition audio, in particular, a driver at C:/Windows/System32/DRIVERS/hdaudbus.sys Disabled it, restarted, nothing changed.

Anything else I can do? Thanks for the help in advance!

I too am seeing high CPU usage. I am suspecting the Nvidia driver since htis is the only major thing I have changed from my Vista install. But I can't seem to pin it down ot the driver.

What version of the driver are you running? (I'm on 191.07)

Bobmeister said:

I've gone through at least a dozen hoops to try and fix this, first here are specs

Intel ExtremeEdition 955 Dual-Core (Pentium D) with Hyper Threading, 3.46Ghz (not overclocking)

nVidia GeForce 9600 GT

FoxConn 975X7AB

2Gb DDR2 RAM

Ok, here's the problem. Fresh install of Win7 (64-bit), open up Resource Monitor and see System Interrupts taking 16-20% cpu. (Not sure if this is important, but it's 75-85% on 1 core out of 4.) Things I've tried:

-Updating drivers for EVERYTHING

-All IDE devices are running in DMA mode

-some people had a problem with a Realtek audio driver for high definition audio, in particular, a driver at C:/Windows/System32/DRIVERS/hdaudbus.sys Disabled it, restarted, nothing changed.

Anything else I can do? Thanks for the help in advance!

Try updating your BIOS, if you haven't already done so.

A "hardware interrupt" is a mechanism used by a hardware component to get the attention of the processor and OS. One or more of the hardware components are generating interrupts so rapidly that dealing with them is consuming almost a 5th of total processor time - an abnormally high number.

If the problem is not caused by a driver "driving" in ways which are confusing to the hardware, then unfortunately the hardware device in question may be simply broken. "Interrupt storms" are one sign of a component which has gone ga-ga.

Does the same thing happen if you boot to safe mode?

SailingNut: Yeah, I've got 191.07 nVidia drivers. Not sure how to go backwards with drivers though...?

Sulfuric Acid: I updated the BIOS recently with FoxConn's LiveUpdate, everything went fine. Haven't tried safe mode, but I will in a few hours and I'll report back.

Just to be clear, I don't have many devices plugged into this thing: just motherboard, cpu, gpu, CD/DVD writer, HDD. That's it. And all of those are less than a year old.

Bobmeister said:

Just to be clear, I don't have many devices plugged into this thing: just motherboard, cpu, gpu, CD/DVD writer, HDD. That's it. And all of those are less than a year old.

Understood. One way to look at your symptom is that one of the devices is attempting to get the attention of the OS far too often.

Well, tried safe mode and problem was still there. Am I right in saying that that might point to the gpu drivers? I can't remember if I had this problem before I installed the newest (191.07)...

In the meantime, I'll check other forums to see if others are having problems with the drivers.

Oh, I just got something (perhaps)! I was tooling around and found the "Performance Rating" application, and all of my stuff was labeled (unrated). So I said wth and clicked "Rate". It took a bit, made it through the gpu tests, I left and came back and it said there was an error, that it "Could not measure processor performance". Is this in any way related?

Bobmeister said:

Oh, I just got something (perhaps)! I was tooling around and found the "Performance Rating" application, and all of my stuff was labeled (unrated). So I said wth and clicked "Rate". It took a bit, made it through the gpu tests, I left and came back and it said there was an error, that it "Could not measure processor performance". Is this in any way related?

Anything is possible, but I doubt this is a direct manifestation of the same problem as the interrupt storm.

Suggestions:

- Ensure that nothing is overclocked or undercooled.

- Update all hardware-related drivers (NIC, video, chipset...) as much as possible. If that doesn't help...

- Rip out all non-essential hardware which the machine can run without: FDD, secondary HDDs, CD/DVD drives, non-embedded NIC and audio cards, other peripheral cards, devices attached via eSATA, firewire, or USB...., and then check to see whether the interrupt storm is still happening. If so...

- Reinstall the OS from scratch without any additional apps, games, and in particular drivers - nothing at all that's not sourced from the Windows disc.

At that point, if the interrupt rate is still this high, you've almost certainly got a hardware defect on your hands. It's possible to glean additional understanding as to which component is generating the interrupts, but you don't want to be going down that complex path until some of these simpler steps have been tried out first.

Well, I ended up ripping out things one by one from my motherboard, doing a clean install of 32-bit 7, and a ton of other stuff and it turns out that it was the cpu that had gone bad. I replaced it with a regular Pentium D 3.66Ghz and it runs just fine now. Thanks for the help, though!