Upgrading IBM Thinkpad to Pentium M 780
 

Hi

I own an IBM T41 Thinkpad and Im about to start upgrading it. Im going to be bringing it from 512MB of RAM to 2GB which is simple enough.

I also want to replace my processor with an Intel Pentium M 780

Will this processor definitely work with my laptop?

Here's the one Im thinking of buying:

http://www.ebay.co.uk/itm/LAPTOP-CPU-Intel-PENTIUM-M-2-2GHZ-512-533-S478B-SL6VB-/230773971099?_trksid=p3284.m263&_trkparms=algo%3DSIC%26its%3DI%26itu%3DUCI%252BIA%252BUA%252BFICS%25 2BUFI%26otn%3D21%26pmod%3D251014574727%26ps%3D54

What are the downside to buying a processor second hand if any? Does performance decrease?

Thanks for any help!

Upgrading the RAM is useful, if you run Gnome or KDE you need at least 1 GB, 2 GB is better.

Don't waste any money on the CPU. It is risky to buy on eBay, it is risky to replace the CPU and most important of all, dropping a different higher performance CPU in an otherwise unchanged mainboard doesn't bring any noticable performance gain.

jlinkels

Raising the amount of RAM will give you a much more significant performance gain than changing the CPU on that system ever will. While buying more RAM is worth the money I personally would only change the CPU if I could get one for almost free, lets say not more than 10€.
Also, the T41 only supports CPUs with 400MHz FSB clock frequency, so the fastest CPU in that machine would be the Pentium M 765.

I have a Thinkpad X31 which uses the same CPU as the T41, but a previous owner has underclocked it to keep it cool and save power. He also gave it 2GB of RAM. It had Ubuntu on it when I bought it, which was very sluggish, but with Salix and Xfce it's fine: a little slow to boot, but OK once it's running. So, I'd agree with the others: give it more memory and run a modest desktop or window manager, but a new CPU would be a waste of money.

FYI, underclocking alone will only slightly help with saving power. If you have options to also reduce the core voltage I would give that a try, that will really save some power.

Im running opensuse with xcfe so its not running badly, could definitely do with some more RAM though.

How check if my cpu is underclocked? Is it possible to overclock?

I think Im still going to upgrade the cpu despite advice, theyre selling on ebay from between £10 - £20 and I think it would be an interesting exercise to change it.

Also, what are the potential problems of buying a second hand cpu?

Cheers

Just look into your BIOS.If overclocking is possible depends on your mainboard, most Laptops don't allow it. Other than that you get one that is defective? Keep in mind that most people would sell a working laptop as whole, not in parts. That can mean that the machine in which the CPU was used before had a defect of any kind, that maybe also had an effect on the CPU.
Also, if you buy a new (used) CPU also buy a good thermal paste, you will need it.

According to Wikipedia, heat generation is proportional to the frequency and to the square of the voltage. A voltage cut will therefore be very effective, but halving the frequency will still halve the heat if that formula is correct.

Err, up to a point. There is a component of power that is due to leakage current and that does not depend on frequency. This is significant on present generation parts, but may not be significant on parts that old (ie, leakage current goes up as geometry shrinks, and back then the geometry may have been sufficiently coarse by today's standards that leakage current wasn't significant, except at really low clock frequencies...or in power save mode, of course).

So, broadly, over a limited range of conditions, the proportionality to frequency does hold true, but not universally, and certainly not if power save allows you to go down to really low frequencies, (err, although power gating may come in as well as frequency scaling, and that throws another factor into the mix).

Ok cheers for the replies. My processor is steady at 1.5ghz so its not under clocked.

Seems the IBM bios are locked. Anyone know of linux overclocking software similar to SetFSB for windows?

If I can overclock this bad boy to 2ghz Ill be chuffed. Id even be happy with 1.8ghz

If you don't want to buy a new notebook you shouldn't overclock at all. Overclocking the CPU to 2GHz (33%) is not a trivial task, you need the appropriate knowledge, it is not just setting the FSB to a higher frequency. Doing such a massive overclock will most likely need an increased core voltage, which will dramatically raise the heat produced by the CPU. It will generate much more heat than a CPU running at 2GHz as stock speed. I really doubt that the cooling system of your laptop is designed to handle that.

General advice: Don't overclock if you don't know exactly what you are doing. Don't overclock if the hardware has any worth for you. Even the best overclocker sometimes fries his hardware.

Point taken.

Well we're back to where we started then: Buying a new cpu.

So...If I manage to install a new CPU without frying my pc with static is it going to work without any software updates for my OS (openSUSE 12.1)?

How do I do a BIOS flash?

I found a fantastic instructional on upgrading the CPU in the t41 from chaos manor:
http://www.chaosmanorreviews.com/ope...l_20070205.php


I want to attempt this partly because of the performance gain but also from an educational perspective since Im starting an Fdsc in Applied Computing soon enough.

IMO its not worth the risks and double-checking, sodding around and work of upgrading.

Looking at ebay.uk it seems that a Pentium M 765 is going for 80quid+. RAM upgrades for the T41 would cheaper, but you'd still be looking at 50quid+ for 2GB. Which is about halfway to getting a intel atom/amd fusion netbook, which would have more CPU power than any pentium M (and faster RAM, and other system busses as well).

There is a pentium M 755 for 37.99 and you can get 2gb RAM for for 36quid so thats 70 odd quid total since the shipping is free

I appreciate and understand people telling me not to do this but as I mentioned Im also doing this out of interest and if no one ever bothered doing things because it was a bit risky we'd never get anywhere.

This laptop is fine it could just do with a kick up the arse so itll last for a few more years, after all, its nearing its 9th birthday!

Please report back on what happened when you replaced the CPU. This is not sarcasm, but sincere interest. My experiences are that replacing a CPU brings negligible speed gain, but it might be observed differently especially if you know that you have spent money and put effort in replacing the CPU. (I am convinved my Lenovo T61 runs much cooler since I have installed the 64-bits version of Debian -- do you believe it?)
Since you seem to want it from a scientific point of view you should not be discouraged by us and it is not an issue whether or not it is really worth it.
Good luck.

jlinkels