Pardon my ignorance, but while reading the many overclocking threads, including this outstanding summary, it seems to me that there is a huge variation in the types of overclocking that individual units support.

Might I ask why this is the case? And is there any remedy if, say, the ideal or ulv clocking profile renders one's n900 unstable? Any further kernel tweaks that can make it work?

For instance, it seems to me that some people simply type "kernel-config load ideal" and live happily ever after, while others struggle to make ulv work with 800 Mhz. What differences (e.g., build quality, quirks in hardware, etc.) make the latter "unlucky".

The variations in the chip manufacturing process are the cause for every chip being a little different. They behave similarly enough to be treated as equal when one stays within the manufacturer's specifications, but outside those limits there are no guarantees.

If you get a "poor" chip, there's nothing you can do about it except change it for another one. With a device like this it would practically mean changing the entire device.

Thanks for the quick reply. A follow-up question: Is there a greater danger of damaging a "poor" chip with overclocking. I.e., if the power-kernel's "ideal" profile causes crashes or reboots, should one avoid overclocking altogether, or simply settle for the "lv" profile?

And practically speaking (and I realize the answers to these questions are largely subjective), how much difference is there between the lv and the ulv and/or ideal profiles in terms of a) battery life and b) long-term stability of the device? I suppose lv with 250-850 is nothing to scoff at, but accounts of 1 Mhz with the ulv profile make me envious.

I think that there is little danger to your hardware in using any overclocking settings such as Ideal. If it doesn't work, just use something less restrictive.

In the long run, maybe you will run into trouble after five years as opposed to seven if you don't overclock. But I doubt even that.

You might remind people who get hysterical about overclocking that their N900s are overclocked already. The question is, can you overclock them more, and the answer is that you usually can.

The same thing goes for power settings like Ideal.

All the included overclocking profiles stay at or under the default voltage when <=1000MHz, so long as you don't go over the default voltage it shouldn't cause any harm (and it most likely won't even if you do, so long as it isn't too much). Also no-one so far has reported damaging their N900 from overclocking.

the Cpu of the n900 in what i read and understand is clocked and is made to clock at 550mhz (by default) but as we get our n900's it is clocked 50mhz higher (600mhz). so, which means, the n900 is already overclocked before you take it out-of-the box.

This is what i read and searched, cant provide sources right now but i am sure someone with enough knowledge will stand and CORRECT my ignorance.