Interrupt service uses 20 to 30 % CPU

Hi there,

Sometime, when my Vaio TT11LN do nothing the CPU usage is 20 to 30 %
Do nothing means:

• No application loaded
• No disk activity
• No network activity.
• No external device is connected to the Vaio.
• No firewall, no antivirus, no anti-spy.

In the Windows Manager, CPU usage is 20 % to 30 % but in the Process tab all processes have 0 % usage.

According to Process Monitor from Sysinternal/Microsoft, a service called Interupt uses these 20 to 30 % of CPU.

In my opinion, there should be a problem with a bad driver or IRQ issue, but I have reinstalled Vista from Scratch from Vaio DVD, and I have the same issue.

I tried to disconnect Wifi and Bluetooth devices, webcam, optical drive, … from ine hardware control panel… CPU usage is still 20 to 30 %. The only way to solve the issue is to reboot.

This issue comes 2 / 3 times a week.

Any idea ?

Thank you for your help.

Denony

 

Why does this matter? Do you expect it to have 0% cpu usage? Sort of like a person having a 0 pulse rate when they're at rest?

 

This is a good explanation of what the Interrupt service is. It is something that is pretty much the norm amongst all computers today.
http://homepages.uel.ac.uk/u0219091/Interrupt.htm

Given that your computer has a 1.2 ULV processor this might spike your processor a bit higher than it would do to a laptop with a more powerful processor.

 

I dunno my Eee 1000h netbook, running an Atom CPU with Server 2003 currently, has 0-1% usage at idle. Both desktops run at 0-1% (one XP, one Vista), and my Lenovo (only other notebook that readily available) is at 0-1% (Vista).

20-30% does seem awfully high. Are your hard drive lights flashing? If there's some drive caching going on, then you might see some.

 

If the OP really wants to get an idea of what's going on, then he'd do a lot better by using SysInternals' Process Explorer to take a look at what's going on with his system - it's got much better access to under-the-hood than the built-in task manager does.

My guess would be that there's some fool driver onboard that's acting up, and is doing a lot more polling of its hardware than it should be doing (that would be a good source of interrupt activity).

 

Have you visited the Sony website and looked for updated drivers?

 

Hi there,

Thank you for your reply.

Most of the time, the CPU is 0 to 1 % in idle. But sometime, it goes to 30 % until I reboot the Vaio. The Vaio is still very quick, but the fan runs when the temperature goes high.

Sometime the issue comes when Vista resumes from hibernation. But all devices works well.

There is no HDD activity even if the HDD light blinks once per second. If I disable the CD/DVD drive driver, the light stop blinking, but CPU is sill at 30 %.

I have red some topic about PIO / DMA issue, but I don't know how to check the mode my Vio uses. I try this tip from Microsoft, but there is no word "channel" on my Vaio and non "Advenced Settings Tab" on devices under IDE ATA/ATAPI controller.

I've check Windows Events logs : no problem.

Is there a way to know which device or driver uses the CPU ? Is there a option to do that in Process Monitor or Process Explorer ?

Thank you.

PS: I have the latest drivers from Sony.

 

It's possible that the vents are clogged and it's getting too hot inside - the interrupts might be being thrown by the thermal sensors if your internal temperatures keep rising and falling around the threshhold temperature at which the fans are triggered. Try cleaning it out, including the vents and the fans (best is to open it up to make sure that all the dust in the fan blades is cleaned out), and see if that doesn't make any sort of a difference.