CPU powers up at half speed (or less)

mfaklis · 26 Nov 2013

I using my 12 year-old Dell Latitude C840 laptop running Windows 7. It was working fine until one day it started to run extremely slow. It has a 2.6 ghz Pentium 4, but it now starts up at 1.3 ghz, at times starts up at 1.3 ghz, or even 800 mhz. Very seldom I can get it to restart at full speed. This is definitely a hardware problem, since when I swap the disk to my old XP disk, This problem still occurs, even though back when I was using XP, it always ran at full speed.

Assuming I can't find the hardware problem, I'm looking for a windows 7 compatible utility that can bump the CPU back to full speed. Recommendations or solutions?

I actually have duplicate C840 laptop I was using to run openSUSE. This slow CPU problem hit the Linux machine over a year ago. I was able to find a UNIX utility that was able to bump the CPU speed back to normal. That machine is currently disassembled in an attempt to isolate the problem by swapping parts.

I'm confident this is not a Windows 7 problem, but I am looking for a Windows 7-compatible solution.

archer · 27 Nov 2013

Hi,

Go to the power configurations and make sure the CPU power is set to 100% maximum for both AC and battery.

You should also download a temperature monitoring program on both and see how temps are running. If the slow one is running hotter, you could have a problem with poor heat transfer from the CPU/GPU ti the heat sink because of an incorrectly attached heat pipe or heat transfer medium.

Check whether the SpeedStep option in the BIOS menu is enabled. If it's disabled it may cause the system running at half speed, whilst CPU is not idle.