There are couple of ways to do this:

1) Make a custom file that you'll load with
and edit FREQS string and remove all unwanted frequencies.

or

2) Write avoided frequencies to "avoid_frequencies" -file. This need root rights.
This will avoid frequencies: 250MHz, 550MHz and 600MHz.

Note: Avoid frequencies will work only with "ondemand" covernor.

sorry for my slowness on overclocking in N900, I dont know whats actually the conservative governor, what it does actually?

I tried to set it and i found that my phone is much warmer and laggier when waken from idling. Besides that, i found that it is much battery consume than ondemand.

my current setting is 250MHz ~ 1GHz, lv settings. sorry for my bad english.

Indeed a fair point raised...
Yes i am aware of the various governors and how they work , shall test conservative to compare performance against ondemand then select which i think is more suitable .

so according to matan, conservative is not safe, but that does nor mean its dangerous right?

UPDATE: i read from here that conservative is suitable for battery powered devices. in pc and laptops though. so no assurance that the same will work on n900. but nothing has been said which governors are safe or harmful for the cpu.

Ditto. On demand is the recommended method for TI OMAP3 devices (The N900 is one of those) because it is more power efficient to finish the task as quickly as possible and return to idle state. Using conservative governor would probably have the opposite effect in term of battery life to what you guys are expecting.

the n900's CPU can switch or change freqs in a split second, and the ondemand governor quickly sets the cpufreq to the max when stress is loaded and jumps to the lowest freq when idle.

so yeah, ondemand is recomended. based on what i read.

i tried both governors and what i notice is they actually have the same effect. (but i have no idea why the conservative gov takes longer time of using the device before it produce heat).

im still experimenting.

What about my choice to allow two frequencies only: 500 and 1000 (both undervolted)? Shouldn't it allow to save battery charge by doing heavy jobs at the highest speed and then jump down to the lowest freq?

on the wiki, cpu sleeps @0mhz when idle. so in idle mode, every settings are the same in terms of battery.

if the device is at stress, i have no idea of which settings (over/undervoltage) consumes more batttery life.

I've spent a few weeks testing the conservative govenor compaed to the ondemand govenor and in my opinion they are both about the same as far as battery usage is concerned (for my usege) however using the conservative govenor had a negative impact on responsiveness due to it being much less agressive in scaling to the max freq.

Edit: I did notice though that the device stayed cooler when multi tasking using the conservative govenor, but not by enough to make it worth using

That said i would still be very interested in testing the conservative govenor again once we have the ability to avoid freqs and adjust the sample rate, as i think it would be much more usefull with a minimal choice of freqs and a shortened sample rate.

for the moment though im sticking with ondemand until the other govenors are fully suported.

It is so amazing that in a few short months overclocking has come from an idea to being fully customizable,
thanks dont even come close to expressing my gratitude for all the work thats gone into this, and it just keeps getting better

The temperature/battery script still giving trouble . works by copying scripts to phone and editing a copy of default config to own freqs/volts etc .restart phone and scripts kick in but at stock voltage , load own default/config and set as default (symlink fron kernel-power settings) , all ok there and restart phone again (not sure how to refresh scripts other ways ?) . now scripts work and freqs/volts correct too so you would think alls good ? well it is until you restart phone cos then you lose .avi file support !! no boot vid or ability to play avi on phone , wmv,mpg work fine just no avi..
really at a loss why the batt/temp script from overclocking wiki combined with titan kernels behaves this way ? means i can use just never restart phone !!! also using ondemand governor based on matan,arbitrabbit,gabby131 earlier posts...

update... not working now at all , script good but file format
not supported for avi. looks like not gonna make it , any ideas ?