CPU runs at high rate for unexplained reason

My laptop lately has been running hot. The CPU usage showing in Task Manager list of running processes might be a total of 15%, but the true total at the very bottom of the box will be 75%, and the fan will be blowing hard. I’ve run BitDefender on full scan, but this persists. Any recommendations of what I might do to find and fix this?

You can usually find the culprit in the running processes. Sometimes its a toolbar constantly updating or too many tool bars. It could be an anti virus program. Start by Googling for those processes that take the most memory. Those often take the most processing fuel as well. Make sure you know what things are. You can start killing unnecessary processes and services temporarily until the usage comes down in a major way. If you kill a needed service, you will be crashing and restarting.

Click on the button at bottom left which says ‘Show processes from all users’ to see what else is using the CPU. In my case the usual culprit is Flash.

Could it be that your processor is overheating and the microprocessor is throttled down to a lower frequency? If you are in Windows 7, look in Resource Monitor at the maximum frequency. It your fan is blowing hard and the maximum frequency is low, that might be your problem.

Are you running Firefox?

I’m going to need that dumbed down. Could you use more words and explanations?

I’m using Firefox 8.0.

When that happens to me, it’s usually the anti-virus software, running supposedly in the background, but actually taking up most of the processor time.

Antivirus and Windows Update are two culprits I’ve identified in the past. To see whether it’s the latter, you can try temporarily disabling automatic updates:

  1. Go into your Services (Start>Run>type “services.msc”>OK or Start>Programs>Administrative Tools>Services)

  2. Double-click the “Automatic Updates” service (if you’re using Windows XP) or “Windows Update” service (Vista or 7)

  3. Set “Startup Type” to “Disabled”

  4. Click OK and reboot.

If there’s no difference, go back in and set the startup type to “Automatic” (Windows XP) or “Automatic (Delayed Start)” (Vista/7) and reboot again.

Alternate (shorter) method of checking:

Start>Run>type “net stop wuauserv”>OK to stop the Windows Update service without rebooting.

(If you’re running Vista/7 and don’t see the “Run” command, right-click the Windows button, click “Properties,” then “Customize,” and then scroll down and select the checkbox for “Run command” and click OK>OK.)

I’m amazed at how timely this thread is! My laptop exhibits almost exactly the same behavior. Automatic updates are off, so it’s not that. McAfee runs on a schedule, so it’s not that (in my case, at least).

I’ve scanned with Spybot, Ad Aware and Malwarebytes, yet find nothing. The processes in the Windows Task Manager that seem to eat up the most CPU are multiple instances of svchost.exe. I do know that sometimes this can indicate a virus, but I would think think that one of the aforementioned programs would have fussed about a virus…

Temperature is my next suspect, but I don’t know how to check it. Is there a utility in Windows XP that tells CPU temp? Is there something free (and safe) that I can download?

What about RAM? The laptop in question has only 512MB.

Thanks, Cardinal, for starting this thread!

I’m running Win 7 64 bit on my laptop. It occassionally goes into a funk in which the fan is blowing like crazy and the responsiveness of the computer degrades to intolerable. If I look in Performance Monitor (I don’t think this existed in Win XP), it shows the maximum microprocessor frequency. If the microprocessor is overheating, the system throttles the clock frequency down. It also does this to conserve power when the computer is not being heavily used.

Whenever my laptop goes into a funk like this, the maximum frequency is shown at a low value, like 10%. The air blowing out is hot. I’m not sure of the cause, but I suspect it is related to overheating. The strange thing is that I’ve run programs that display the core temperatures and they don’t indicate a problem.

512 MB? It sounds a bit on the old side. If it’s old it’s likely gummed up with dust and lint inside.
If you have the patience and manual dexterity for it, you can unscrew the back and have a look yourself. Get some canned air to blow out the dust bunnies.