Underclocking - How slow can I go?

[NeonBlack]

I recently inherited a laptop. It has a 2.7 GHz processor, but only 192 MB of ram. Since the battery life is a little under 2 hours, and I figure that this amount of ram could not possibly take full advantage of the cpu speed, I decided to underclock the processor to save battery life until I find some more memory. My question is how slow can I go without noticing a huge difference? From my memory of PC specs from a few years ago, I am guessing that a computer with 192 MB would have no more than 800-1000 MHz, but I don't know if this is optimum.

[Cap'n Refsmmat]

I had a 733MHz computer with 384MB RAM and it ran reasonably well with XP.

 

I'd suggest just using automated CPU scaling, which changes the frequency based on how much CPU load there is.

[Pangloss]

You'll probably be better off simply replacing the battery. The decline rate on most laptop batteries (lithium ion) is something like 20-30% per year. So if it's two years old it's only got half its original up-time.

 

And it's really consistent, too. I've never seen a two-year-old laptop with the original battery that stayed awake for more than an hour or two, even with conservation features turned on.

[YT2095]

the only real Lower limit is that of the refresh cycles for Dynamic RAM (RAS and CAS strobe) these chips are CCD based and need regular strobing to hold the memory integrity.

 

other than That, if all the IRQ are set correctly there`s no real lower limit

 

in fact if you replaced all D-ram with S-ram you could even run the thing in Step Time!