How to throttle a P4 CPU in a LAPTOP? :o

neilbell · Post by **neilbell** » Thu Aug 17, 2006 4:51 am

Hi guys,

Okay, my girlfriend has a dell laptop with a shockingly inappropriate P4 2.2GHz CPU. From things I have read about these models (SmartStep 250N, or smartPC in UK), you can greatly improve cooling by removing the rubbish heat transfer pad and applying some AS.

However, what would REALLY help is a utility that can throttle the P4 clockspeed based on demand, just like AMD C&Q. Is this at all possible or does it require the chip to support this kind of functionality? Most of the time it is just browsing or simple desktop programs, so it really doesn't need the full 2.2GHz. I am looking to improve battery life AND reduce heat.

Any suggestions welcome.

Cheers,
Neil

jaganath · Post by **jaganath** » Thu Aug 17, 2006 5:18 am

Is this at all possible or does it require the chip to support this kind of functionality?

The chip needs to support Speedstep (and the motherboard and BIOS too). This webpage has a list of Dell laptops that support Speedstep:

Bay Wolf's Speedstep FAQ

It doesn't look like yours is on there. You could try changing the power profile in the Power Options bit in Control Panel and see if it makes any difference.

Also try this:

SpeedswitchXP - CPU frequency control for notebooks running Windows XP

neilbell · Post by **neilbell** » Thu Aug 17, 2006 7:10 am

thanks jag, I'll give it a go. It looks like the only option really, so anything would be good.

Towermax · Post by **Towermax** » Thu Aug 17, 2006 11:01 am

Take a look at Notebook Hardware Control (NHC).

http://www.pbus-167.com/nhc/nhc.htm

I'm using it on my Sony laptop with a Mobile P4 2.4GHz. NHC keeps the CPU idling at 1.2GHz and increases the CPU speed as necessary under load--so-called dynamic switching.

It also allows you to underclock ATI's mobile video chipsets, saving additional heat and power.

neilbell · Post by **neilbell** » Fri Aug 18, 2006 3:35 am

thanks towermax. Sadly this is a standard P4, not a mobile (from what i can tell). I think it came just before the widespread use of Mobile chips.

I will try that utility but I get the impression that a chip needs to have specific support for this function. Never mind. I can still clean the heatsink and apply some AS5