My 5 year old dell laptop (8600) has suddenly lost processor speed.

May 22, 2009 5:54 PM

My 5 year old dell laptop (8600) has suddenly lost processor speed. Techy details after the break...

Inspiron 8600 running XP Home with Intel Pentium M 1.7 Ghz processor has stopped showing it's clock speed as 1.6something and now reports either 592 Mhz or lower.

Computer really drags (two firefox windows nearly brought me to a halt just then so it doesn't seem to be a speed step thing (i.e. the computer isn't throttling back the processor and then letting it go flat out when needed). The laptop is plugged in to power and set to be "always on" in it's power scheme which I believe should force it to be running at full speed.

Today I was trying to speed up the computer for working with Cubase. I changed settings as follows;

Visual Effects - adjust for best performance
Paging file size - changed from "no paging file" to "3070 MB" which was the recommended setting on the Virtual Memory Tab.
In TweakUI I unchecked "optimize hard disk when idle".

I have changed all of these parameters back to their original settings.

The only other thing I did was to blow some air from an air cannister into the vents on the laptop to try to clear some dust to help the pc cool itself.

I have since;
- installed SpeedswitchXP to see whether I could force anything that way and,
- Had a look in the start up settings (reports as a 1.7 Ghz processor running at 600 Mhz) but doesn't let me change anything (Dell crippled BIOS)

Any ideas what might have caused this change for the worse? Needless to say Cubase is not a possibility any more and neither are Sony Vegas or Photoshop so there goes my three pronged creative effort!

posted by merocet to computers & internet (9 answers total)

Sounds like something got changed in the BIOS. That would certainly be the first place to look.
posted by Chocolate Pickle at 6:07 PM on May 22, 2009

Hi Chocolate Pickle I checked in the BIOS and (start up settings mentioned above) and all I get reported is that I have a 1.7 Ghz processor running at 600Mhz. No option to change anything.
posted by merocet at 6:13 PM on May 22, 2009

Are you sure it's always running at the slow speed? Mobile processors underclock themselves to save battery and minimize heat when not in use. How are you checking the clock speed within the OS? Does it increase when running CPU intense apps?

Or perhaps it is overheating and that is causing it to remain underclocked. Dells website is usually pretty good with their diagnosing section for their laptops, maybe have a look there to see if it is a symptom that has a list of possible causes.
posted by Sonic_Molson at 7:06 PM on May 22, 2009

Yeah I addressed the underclocking question above. It's not doing that, it's maxing at 592 Mhz and going no further. I've been checking the speed with CPU-Z.

Should have mentioned that I've trawled the Dell support search function and pretty much every corner of the internet I can google too without turning up anything that matches this specific problem.
posted by merocet at 7:18 PM on May 22, 2009

Can you boot up using an Linux live CD and see if the same CPU info is reported there?
posted by bottlebrushtree at 7:34 PM on May 22, 2009

I just took out the cooling fans and blew some canned air through them and through the vents dislodging half a metric tonne of furry crap. Reseated the memory and pushed everything else I could find into place to make sure of tight fits and then screwed it all back together and restarted and alakazam we're back in business showing 1.69 Ghz and things are shooting along swiftly.

Thanks for your efforts all who tried.
posted by merocet at 7:48 PM on May 22, 2009

I have almost exactly the same laptop and I use i8kfan control to monitor this stuff. It seems like your CPU was getting too hot, so the speedstep logic kicked in to prevent it from damaging itself as Sonic_Molson suggested. The program I just linked should serve as a good indicator in the future if the CPU is getting too hot, so you can just blow out the dust again.
posted by spiderskull at 10:18 PM on May 22, 2009 [1 favorite]

Another thing that can kill your computer's speed is the Hard Disk access switching from DMA (fast) to PIO (slow) (windows does this sometimes when it thinks there might be a problem with the disk, but never switches it back). This slows things to a crawl because any disk access - such as paging - is super slow.

To check, see here
To fix, you can try their suggestion, or just uninstall the disk controller and reboot. Windows should auto detect the controller and hdd and switch back to DMA.
posted by nielm at 12:33 AM on May 23, 2009

This can also happen when your power adapter isn't recognized as an official Dell adapter.
posted by PueExMachina at 5:13 PM on May 23, 2009