Hardware Interrupts Using 30% of CPU

jonathan142

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Hello, recently I bought an Antec earthwatts 500W PSU. When I turned on the computer after installing it CPU usage was about 30% at idle. According to Process Explorer, that 30% is Hardware Interrupts. I know this only popped up AFTER installing the new PSU. Unfortunately, in trying to find a solution on google no one else with the problem seems to have solved it in a way that works for me, and I've already checked my IDE ATA/ATAPI controllers in device manager, and they are all set to DMA if applicable. I tried the old PSU and the hardware interrupts is still there. Safe mode, it's still there, and I also tried the RAM, only using 1 stick at a time to test if one is broken but it didn't solve the problem.

Because of this, I'm guessing it is the CPU, hard drive, or motherboard. What comes to mind is I did remove the heat sink when I first put in the new PSU, and I had some troubles as one of the two sockets for the securing screws for the heat sink seemed to sink down lower than it should be, so that it was actually under the motherboard and I had to push on the other screw socket to push it back up above. In the course of this the heat sink would have rubbed against the CPU itself and I wonder if something was messed up, though I would think that would make the CPU not work rather than give this strange hardware interrupts. Is there anyone who has experienced this? Is there a way to test if it's the hard drive? Is it possible just to unplug it and run the computer without it?

I appreciate any help.
 
How do you know that it's hardware interrupts? By themselves they do absolutely nothing unless you have code to trap them and do something. Replacing the PSU can't cause that issue, but why did you remove the HSF? There wasn't enough clearance to install the PSU?
 

Felicia

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Hi, I had the same problem a few years back. It turned out to be a bad sector on the hard drive that the system was trying to continuously read. I solved this by running "chkdsk" in dos mode. It moved the information on the bad sector to another location and my cpu usage was back to normal. Hope this helps you.
 

jonathan142

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I'm not sure what you mean by code to trap the hardware interrupts, but I know it's here from running Process Explorer, which tells me the CPU usage of it (it does not show up under Task Manager). I removed and put back the heatsink as it was blocking access to the motherboard power connector. Thanks for the replies, I will try to check the harddrive.
 

jonathan142

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Unfortunately checking the harddrive didn't do anything. My CPU usage is 30% idle on the Task Manager. Where is the Check Kernal times box?
 
View, Show Kernel Times.

To determine if the disk is causing that issue, create a BartPE disk and boot from it. Then run Process Explorer to see if the issue still exists. It could also be caused by the video card or any other device that uses hardware interrupts.
 

AdmV0rl0n02

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This is sometimes caused by a fault within the windows or IDE drivers.

The system goes into PIO mode, even though it says its running as DMA.
When you find this, go to control panel, system, device manager, and remove the IDE controllers, Primary and Secondary.

Reboot.
The devices will get re-installed back to DMA working state.

This happens because the driver detects a timing or crc type error when in use, and degrades the system to guarantee data integrity. Change / fix your cables/update the drivers.

AdmV
 

jonathan142

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I'm not sure what kernal is, but in the CPU usage display while idle most of the bar is red, only a sliver is green. The green gets larger if I do something.
 
It proves that the kernel is doing most of the work, i.e., interrupt handling, I/O, etc. You'll have to disconnect your hard disk and boot from a BartPE CD or DVD. Then check if you still have the hardware interrupt issue. I doubt the hard disk itself is the source of your problem, but disconnecting it should at least prove that all other components are not the source of the issue. Narrowing down the issue to the hard disk or software will be a step in the right direction.
 

jonathan142

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Alright I couldn't find any blank CD's in my house, tomorrow I will buy a pack. Also the instructions mention using Windows XP installation files, not just the already installed windows data. Does that mean I need to have the original Windows XP installation CD, because my computer came with it pre-installed and HP doesn't give out backup CD's with their computers.
 

jonathan142

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I should ask this ahead of time; how do you boot from the CD drive? If the CD is there and I turn on the computer without a hard drive, will it be automatic? Also how will I be able to tell if the interrupts is still there, since Process Explorer is saved onto the hard drive? I guess you can use task manager still?
 
If your system is configured properly, the CD-ROM should be before the hard disk in the boot device list. The CD-ROM drive will be ignored unless a bootable CD is inserted. Process Explorer will be available if it's on the BartPE CD that you created or on a USB key.
 

jonathan142

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When I try booting with the disk it tries to load the BartPE, but I get an error "\i386\system32\ntoskrnl.exe could not be loaded error code 32768". The site's FAQ section says I did not slipstream my service pack to my windows installation files correctly, do you know what that means?
 

jonathan142

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When I try to slipstream, the command prompt is stuck on C:\Documents and Settings\HP_Administrator, cls won't clear it. Typing in the integrate command, it says the filename, directory name, or volume label syntax is incorrect even though everything typed seems in order.