What is causing my computer to slow down and how can I fix it?

  • Thread starter CRGreathouse
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In summary: Since you're using a DVD drive, it might be worth trying the steps at http://sniptools.com/vault/getting-back-to-dma-mode-in-windows-xp. to fix it.Since you're using a DVD drive, it might be worth trying the steps at http://sniptools.com/vault/getting-back-to-dma-mode-in-windows-xp.
  • #1
CRGreathouse
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I'm running Windows XP on a dual-core notebook and I noticed that sometimes (like now ;)) the computer slows down dramatically as though under heavy load, but the task manager reports nothing: the system idle process claims 97% of the CPU and there's only ~500 MB of RAM in use (on a 2 GB system). But the fans run loudly, and the task maanger does report (in a contradictory way) that CPU usage is about 55%.

Any thought? I do have "show processes from all users" checked.
 
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  • #3
It is just a wild guess, but if the fans run, perhaps your notebook is overheated so it automagically slows down? I was never interested in details but some processors (especially those targeted at notebooks) have fancy solutions implemented to save on energy and to diminish chances of overheating.
 
  • #4
The laptop does have automagic slowdown (Intel's SpeedStep), but it wasn't on at that time.

Process Explorer may have found the problem. For a decent chunk of time, maybe two minutes, there was 40-50% CPU use for "hardware interrupts". Should they really take that much juice?
 
  • #5
On occasion, I have an issue with my setup in which the Bluetooth drivers are trying to install devices it detected [which I don't want it do]. This eats up my CPU time as it struggles to install these devices. So, I have to manually kill off the process. (If I allow it to finish, the install eventually fails... so I kill it off early.)

So, something like this might be an issue.
Is there a particular process that is using up the CPU? Process Explorer can help identify the process.
 
  • #6
robphy said:
So, something like this might be an issue.
Is there a particular process that is using up the CPU? Process Explorer can help identify the process.

Process Explorer calls the process that I identified above "hardware interrupts".
 
  • #7
CRGreathouse said:
Process Explorer calls the process that I identified above "hardware interrupts".

possibly useful discussions:
http://forum.sysinternals.com/forum_posts.asp?TID=2064
http://forum.sysinternals.com/forum_posts.asp?TID=7775
http://forums.tweakguides.com/showthread.php?t=3733 [Broken]
 
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  • #8
Thanks, I'll look into that.
 
  • #9
CRGreathouse said:
But the fans run loudly, and the task maanger does report (in a contradictory way) that CPU usage is about 55%.
Since you have two CPUs that likely means that one of the cores is running 100% running a single threaded job.
 
  • #10
MeJennifer said:
Since you have two CPUs that likely means that one of the cores is running 100% running a single threaded job.

Yes, certainly. That's why I mentioned that I was a running dual-core.
 
  • #11
robphy said:
http://forum.sysinternals.com/forum_posts.asp?TID=7775

That did it for me! Or at least found the problem, which I trust I can fix. My hard drive went from DMA to PIO mode, so every time I used the hard drive everything slowed down.

I'm playing with
HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\Scsi\Scsi Port 0\DMAEnabled
now; hopefully this works.
 
  • #12
OK, it's solved. I deleted the driver for the primary IDE and rebooted twice. Now the hard drive is back to DMA and the computer is running at least four times faster.

Thanks a lot, robphy!
 
  • #13
There is a 'feature' of windows from XP onwards, after a certain number of drive errors it automatically switches to PIO mode.
This is a problem with DVDs, if you play a badly scratched disk it assumes the errors are due to the drive and switches to PIO which is often too slow to play movies.

See http://sniptools.com/vault/getting-back-to-dma-mode-in-windows-xp [Broken] to fix it.
 
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  • #14
Ouch, that's good to know - I noticed my dvd drive running rediculously slow a few months ago and found it in PIO mode. Gotta love MS! What they should do instead is slow down the rotation of the disk, try to read the area a few times at a lower speed, then decide it is a disk error.
 
  • #15
mgb_phys said:
There is a 'feature' of windows from XP onwards, after a certain number of drive errors it automatically switches to PIO mode.
This is a problem with DVDs, if you play a badly scratched disk it assumes the errors are due to the drive and switches to PIO which is often too slow to play movies.

See http://sniptools.com/vault/getting-back-to-dma-mode-in-windows-xp [Broken] to fix it.

Yes, this is an intentional feature -- though I thought it started in Win2000, not XP. Regardless, I happened to try that set of steps (though I didn't read that page) and they failed for me. Only deleting the driver worked.
 
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1. What is hidden CPU utilization?

Hidden CPU utilization refers to the amount of processing power being used by programs or processes that are not visible to the user. This can include background processes, system maintenance tasks, or malicious software.

2. How can I check for hidden CPU utilization?

To check for hidden CPU utilization, you can use a performance monitoring tool such as Task Manager (Windows) or Activity Monitor (Mac). These tools will show you the overall CPU usage as well as a breakdown of which programs or processes are using the most CPU.

3. What are the potential causes of high hidden CPU utilization?

High hidden CPU utilization can be caused by a variety of factors, such as malware or viruses, outdated or poorly optimized software, or system maintenance tasks running in the background. It can also be a sign of insufficient hardware resources for the tasks being performed.

4. How can I reduce hidden CPU utilization?

To reduce hidden CPU utilization, you can try closing unnecessary programs and processes, updating software to the latest version, and running regular malware scans. You can also consider upgrading your hardware if it is not powerful enough to handle the tasks you need to perform.

5. Can hidden CPU utilization cause performance issues?

Yes, high hidden CPU utilization can cause performance issues such as slow response times, lagging or freezing programs, and overall system slowdown. It is important to monitor and address hidden CPU utilization to ensure optimal performance of your device.

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