notebook P4 throttle (how to underclock ?)

[stefbin]

hello,

my notebook has an intel P4 2.66 installed, and runs on 133 fsb
when i disconnect ac-power (=runs on battery power), the fsb throttles down automatically to 83.3 fsb (cpu 1.66ghz)

how can i throllte down the cpu/fsb when running on ac-power ?

i want to do this for looking at movies without the fan spinning for 30 sec every 5min (happens only when running on ac-power), so if i can throttle the fsb down, my cpu wont be that hot/noisy anymore ...

thx

 

[Abhi]

Which notebook is this?

 

[stefbin]

gericom hummer fx 5600

p4 2.66, fsb 133/533
1gb ram, 2*512 ddr
ami bios, american megatrends mainboard
toshiba harddisk 60gb, 4200 rpm
toshiba dvdr-RW
geforce fx 5600go, 128 mb

 

[LTC8K6]

Can you set the power management for max battery life? That might do it. Then again it might ignore that if it's plugged in.

 

[stefbin]

thx
indeed, i just tried it but the power schemes doesn't seem to affect fsb

 

[LTC8K6]

I thought the mobile chips changed their multiplier to slow down rather than their FSB? Maybe you have a desktop chip though?

 

[stefbin]

yes, it's a desktop chip, a plain P4 2.66, not a p4-m

cpu: intel P4 2.66, northwood, rev. C1
chipset: intel i845PE
southbridge: 82801DB (ICH4)

(according to cpu-z)

 

[stefbin]

it should be do-able, right ?

whenever the ac-power is unplugged, the fsb throttles down ... does somebody knows how it works ?
i would like to be able to set it manually while still running on ac-power

 

[LTC8K6]

You might be able to drop the FSB to 100 in the BIOS. I'm not that familiar with notebooks, though.

 

[stefbin]

no, that's part of the problem: i'm unable to change anything like that in the bios !
but since it runs automatically under windows, i should be able to acces it somehow ...