is there a way to speed fsb down?

[bzzz]

for example, from 533 to 400. just to improve battery life. thanks.

[Kyocera]

I think this is what you are looking for?

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

[bzzz]

I think this is what you are looking for?

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

AFAICS, it controls voltage/multiplier, but not FSB.

[christopher_wolf]

Hmm, I don't think you can control FSB directly on an Intel Chipset.

http://www.aoaforums.com/forum_new/gene ... print.html

There seems to be hardwired circuits in there to prevent that.

[bzzz]

thanks, christopher_wolf.

then I wonder will my t43 work if i replace 533fsb dothan with 400fsb one?

thanks.

[davidspalding]

What makes you think you're going to improve battery life by downgrading your processor? Even if you can yank the processor and slip in a lower bus-speed one....

[Troels]

What makes you think you're going to improve battery life by downgrading your processor? Even if you can yank the processor and slip in a lower bus-speed one....

533Mhz FSB Dothan second gen "Sonoma" = max. 27W thermal power dissipation
400Mhz FSB Dothan first gen = max. 21W thermal power dissipation

[davidspalding]

Okay. That tells me that it can run hotter. Doesn't mean that it WILL run hotter, and consume more power.

Perhaps Intel has some information on this....

[dino]

thanks, christopher_wolf.

then I wonder will my t43 work if i replace 533fsb dothan with 400fsb one?
thanks.

Check out
http://download.intel.com/design/mobile ... 526401.pdf

It doesn't list Pentium M with 400FSB but it does list Pentium LV and ULV 400FSB.

[Esben]

I doubt you will notice a difference in battery life at 800 MHz versus 600 MHz, if they both run 0.7v.

The CPU is not the major factor of power usage, at that low speed.

[bzzz]

I doubt you will notice a difference in battery life at 800 MHz versus 600 MHz, if they both run 0.7v.

The CPU is not the major factor of power usage, at that low speed.

probably you're right, but T42 is claimed to run upto 5h from 6c battery, while T43 - upto 4h. probably that's due to GPU ..

[davidspalding]

Who claims ...? If you're thinking of mucking about with the chip on your mainboard, paricularly downgrading from the system's design, I wouldn't do it just based on conflicting marketing information. Battery life is one of items most likely to be covered by "your mileage may vary," based on power configuration, use, etc.

[bzzz]

Who claims ...?

tabook does. and I consider this 5h to 4h downgrade in official papers to mirror the real fact that T43 consumes significantly more power than T42. so, my question is about the source of that: CPU or 533fsb or X300 or something else?

[christopher_wolf]

Ehhhh, I am not so enthusiastic getting that kind of information from tabook; the biggest change that I can see is the minimum clock on the T43 vs the T42. On my T43, I can lower it to 800MHz, but, if I remember correctly, it can go down to 600MHz on the T42. I still can't see why it is claimed this reduces battery life so much. I haven't seen much of a difference between my T43 and my friend's T42; I have even managed to match the duration of the T42 on battery. I am still very careful about reading the battery estimations from there; there are many factors that affect the battery duration of the laptop. They always have disclaimers on the webstire about how they measured the battery life.

[bzzz]

I haven't seen much of a difference between my T43 and my friend's T42; I have even managed to match the duration of the T42 on battery. I am still very careful about reading the battery estimations from there; there are many factors that affect the battery duration of the laptop. They always have disclaimers on the webstire about how they measured the battery life.

only I can add here is that many T43 reviewers have noted shorter batter life. indeed, I dont know for sure do they use real numbers or specs.

[christopher_wolf]

But can you say, *for sure*, that the FSB is what does it? If you can't say that with at least 95% assurance, then perhaps it is not the best idea to try and lower the FSB just to get a few more minutes of battery life.

[bzzz]

But can you say, *for sure*, that the FSB is what does it? If you can't say that with at least 95% assurance, then perhaps it is not the best idea to try and lower the FSB just to get a few more minutes of battery life.

indeed, this is why i'm asking

[davidspalding]

Who claims ...?

tabook does. and I consider this 5h to 4h downgrade in official papers to mirror the real fact that T43 consumes significantly more power than T42. so, my question is about the source of that: CPU or 533fsb or X300 or something else?

LOL. Dude ... that is a sales tool. It is not some authoritative performance spec. Do some googling for anyone with "Batterymark" tests on similarly equipped T42s and T43s. That might be compelling....

Instead of Frankensteining your laptop, just sell it and get the T42 of your dreams with the proceeds. Best of luck....

[bzzz]

LOL. Dude ... that is a sales tool. It is not some authoritative performance spec. Do some googling for anyone with "Batterymark" tests on similarly equipped T42s and T43s. That might be compelling....

probably you're right, http://www.pc.ibm.com/ww/thinkpad/batterylife.html

from those numbers, it looks like T42 wins by 30-40mins. not a very big difference, but quite visible ...

[christopher_wolf]

Yes; but the test doesn't state at what frequency they ran the machines at; was it full out (not likely)? Was it at minimum? Did they use a specialized power setting? It makes a difference since the T43 can't go lower than 800MHz, from what I have seen, while the T42 can go down to 600MHz. That in itself can skew the results if you use the "minimum" frequency setting for both machines. When I first got my T43, I was curious to see how it would compare to my friend's T42; so we both charged up the high-capacity 9-cells then set them on the same settings a tad above 800MHz. They both lasted for over 4 hours then started to give low battery warnings 30 minutes after that. The chips are different as well as the FSB; so were the graphics cards (significant power consumption). The difference that I saw was alot closer than what they give in the Battery Test, more like 10-15 minutes rather than 30-40 minutes. If one is *really* interested in getting the most out of the battery, why not get the T40 they specc'd in that *.pdf and undervolt it? There isn't that much of a difference between the 1.6GHz Banias in the T40 in that test sheet and a 1.86GHz in a T4; you can get 7:49 hours of battery life on that...Sounds to me like a great all-day computing platform. My research friend already knows this and does go for *long* periods of time with his T40.