[infinitevalence]

!!!!! This is not a definitive guide to overclocking, it is MY quick and dirty way to get a fast overclock. This guide will not maximize your performance, it will only enhance it. If you want to find the maximum performance read some of the stickies. As usual I and the owners of the forums take no responsibility if you damage your stuff. You break it you bought it. Use your brain when overclocking keep an eye on temperatures and don't use unreasonable voltages, you can damage your equipment if you don't. This guide is a living document I will update it as corrections are made and new techniques are adapted. Please do not post flames, keep it to constructive information or questions regarding this guide. !!!!!


More and more people are buying laptops. With this comes the desire to overclock and under volt the Pentium m. This is a quick guide to doing just that.

For those who have a laptop based on the 915 chip set and have a 400mhz FSB processor there is a simple wire modification that will force your processor to run at 533. I do not recommend getting a processor with over a 17 multiplier as there is not guarantee that it will boot. So your best options are the 735 which should do 2.26ghz and the 725 which should do 2.13ghz.



The first thing your going to need to do is make the wire for this mod. I use a single strand from some braided speaker wire. Cut it to a length of about 4-5mm. Then bend it into a U shape from the middle of the wire. I find that the best way to insert the wire is using a small pair of needle nose pliers.



Now that you have the wire insert it into the two holes indicated in the picture. As you can see I have already placed my wire in the correct place to assist you in finding it on your laptop. Now pop your Pentium M into its socket and lets boot the sucker.


Now that you have it modded to run at 533FSB your laptop is going to use allot more battery power. That's where the undervolting comes in. Download .NET and Centreno Hardware Control (CHC). This program lets you set up voltages and multipliers. I use dynamic switching so that as the computer requires more power it simple uses one of my preset multipliers and voltages.

To test use prime95 set it to torture test large FFT and let it run at the default voltage for a while, then using CHC reduce the voltage, again let prime95 run until you feel satisfied that it is stable. Repeat this process until you find the LOWEST stable voltage at your maximum multiplier and then drop the multiplier to a lower number. Repeat again testing with prime95 until you find the LOWEST stable voltage for each of the multipliers you wish to use.

That's it folks your done, now not only are you getting a top of the line CPU for pennies on the dollar, but your also getting the most battery life you can out of your new powerhouse of a laptop.

If this seems short on information or you just want to learn more about overclocking the Pentium M processor Ozzlo has a very information rich, quality guide here. Even if you want to use my fast method i highly recomend reading his guide to get a real understanding of what your doing to your laptop it can only help you.

[Bender]

I do something similar to my laptop. I have a tiny Toshiba R200 with a Ultra low voltage Pentium M 1.2 GHz 2 MB cache. Stock voltage is 0.940v for 12x multiplier. I can run it as low as 0.812v for 12x. To dynamically control the speed and voltage I use Crystal CPUID. This doesn't affect the speed of the laptop but the battery lasts longer and the laptop stays cooler.

[infinitevalence]

wow... you cant get lower than .812v? at my lowest setting on my laptop i am 100% stable at .700v which is as low as i can go.

[Elif Tymes]

his is 1.2Ghz, yours is more than likely 800 odd mhz. a 400Mhz speed difference there

Nice guide though I've doen this on my P-m, @ 2.13Ghz I can run a cool 1.196v stably. and @ 800Mhz I am running .7 as well.

[Bender]

I just finished stress testing the Pentium M in my Toshiba. Here are the lowest voltages I could run at each frequency.

1200 MHz 0.828v

1000 MHz 0.764v

800 MHz 0.700v

I wish I could test voltages below 0.700v. 800MHz was as fast as I could run at 0.700v but I can throttle down to 600 MHz. I have crystal CPUID setup to throttle the CPU. Centrino Hardware Control looks nice, I may have to give it a try. My laptop has active cooling but its an incredibly tiny fan that hardly runs. I should have close to 5 hours of good battery life now

[infinitevalence]

Thats very nice, mine would not quite run at that low a voltage. at 10x i need 1v and 8x .950v

The thing i really love about the pentium m is the battery life. It honestly shocked me when i was able to overclock my cpu close to 600mhz and still extend my battery life! I have never been as happy with a laptop as i am now.

[Bender]

I love how you are running faster with less voltage. I wish I could do that with mine but I dont believe its possible. I have a 915 chipset as well but my CPU I dont think uses a socket. I dont think a socket is possible on a .75" thick laptop. If the CPU pins went through the back of the motherboard the wire trick would be possible.

[infinitevalence]

yeah, thats the only way i think... they may but more than likly its just Micro BGA and soldered right to the motherboard. It would be worth opening up and looking though, because that would be totaly bad ass if you could just short the two pins together off the back of the motherboard

[Alpha_One]

Hey thanks for the info on the Notebook Hardware Control software. I've used it on the laptop below, running 1.6GHz @ 1.004v (stock clocks, undervolted). While performance is the same, battery life has been significantly extended!

[ozzlo]

just something you may want to add..
some processors (depends on the individual processor) may need a voltmod (especially at faster speeds like 2.26ghz & 2.4ghz) to be 100% stable... that is a 566mhz overclock afterall...



I am in the middle of building a PENTIUM M VOLTMOD GUIDE... I'm considering linking to this for a get started guide if that's ok with you...?

[infinitevalence]

fine by me, this is like all my guies simple and low detial. I try not to overwhelm noobs with lots of info about overclocking, most just dont care, so i give them what they want, if they break it then they can do the research to find out why

[ozzlo]

Ya I'm starting to head down that road also... it's too much work to get everybody to care.... just like that fact that 9 out of 10 people that voltmod their comp with a guide that just shows how to do it and dosen't explain whats going on NEVER REALIZE that after a volt mod the voltages represented in NHC are incorrectly reported and that you must calculate what they actually are based upon what you modded... just too much effort for some people...

[infinitevalence]

hey got a quick q for you, do you notice a difference in battery life with dual channel memmory on your laptop?

[infinitevalence]

just a little bump for people looking for a speed improvement

[ozzlo]

I don't see how dual channell would affect battery life very much... those DDR 2 sticks are more power freindly than the old DDR 1 sticks...

[imgod22222]

Can this volt-mod be used with any chipset or just the 915. I have a Intel i855PM (Benias core) at 400FSB
EDIT:
never mind, it only works on a 915.

The Chipset:

The purpose of the chipset, relevant to this modification, is that it controls the speed of the FSB. There are two chipsets being used in conjunction with the Pentium M processors: the 855 and the newer 915. The 855 series chipsets only support a FSB of 400MHz. The 915 chipsets can operate at either 400MHz or 533MHz, and thus is what this howto is based on.

Source: http://www2.ijib.com:1337/phpbb/viewtopic.php?t=3