CPU Load and Fan Speed Fluctuating Heavily

Hi there,

For the past few months, my CPU load has been rapidly increasing and decreasing (between 15% and 100% for all four cores), along with the fan speeding up and slowing down for no good reason - while the computer is idle. The fan will go from 1000RPM up to 10 000RPM. I turned off all my startup programs, but the problem persists. I have recently updated all my drivers and my BIOS (I did this to try and amend the problem).

Here are my computer specs:

Operating System
MS Windows 7 Home Premium 32-bit
Intel Core 2 Quad Q9505 @ 2.83GHz
Yorkfield 45nm Technology
4.0GB Dual-Channel DDR2
AMD Radeon HD 6870

What could the reason be for this?

9 answers Last reply
More about load speed fluctuating heavily
  1. The fan speed increase's when the CPU gets hotter.So whenever the CPU is maxed out at 100% usage it gets hotter.

    Usually random spikes in CPU usage are associated with a virus.Try running a anti-virus software to see if it can clean it up.If the problem persists I suggest a fresh install of Windows.

    Another way to see if it's a process/application/software causing it is to boot into safe mode.If the problem goes away then you know it's a process or application.
  2. One of the possibilities could be a failing HDD, second could be background processes in windows itself and the third reason could be virus activity.
  3. Thanks for the replies. I ran a virus scan with AVG full edition, and there were no threats detected. Then I rebooted in Safe Mode, but even while my computer was rebooting, it was very loud, so the fan was obviously running fast then, without Windows running. So this means that it's not a process? How would I check for a failing hard drive?
  4. Download Crystal Disc Info and it'll give you the SMART report on the drive.


    Another thing I'd like to know is if the rig is clean of dust and fabric fibers.
    There is a possibility of bad thermal conductivity between the processor and it's heatsink, if
    1: The rig is too old, thermal paste is dead.
    2: The fans have got clogged with dust and fibers.
  5. Thanks, I've run run Crystal Disk Info, and both hard drive have Good health statuses. Is there anything in particular I must tell you from this report?
    It could be dust - my friend added new thermal paste about 5 months ago, how often should it be applied?
  6. Not too often, thermal paste needs to be applied only if it's gotten too old and you feel temps are staying high even under normal states.
    Did the sudden fluctuations start after the new thermal paste was applied? or did they just start recently?
    You need to blow the dust and dirt out of the case ASAP, use a compressed air can if you can get your hands on one.
  7. i have seen these sysmtoms when a virus or worm is active on a system. they run cycles that max out the cpu for a few seconds causing the fan to speed up and slow down...
    get the usual suspects (for me, malwarebytes, spybot, avira free) and scan
  8. You can look in Task Manager to see what Processes and Services are spiking the CPU usage. It could be anti-virus software, etc. running in the background if you do not have a SPAM virus.
  9. I have checked the Task Manager during the spikes and the only thing that is high is System Idle Process. What exactly is that?
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