Wolfgang Rupprecht wrote:
> The important thing about the halt instruction is that it will put
> large parts of the CPU and system into a low-power state.  Taking this
> out doubles the power usage on a Vaio 505tx.
Whoa! I'm recosidering the Power of Halt! :) (but, I used that before)
Anyway, I never noticed that big behaviour on either OS, as I always
have a low-pri program running 100% of the time (and no, it isn't a
do_nothing_but_wating_electricity ;)

> clock-interrupts.  Having the CPU interrupted and power-ed up 100
> times per second has got to take its toll.  Has anyone played with
> tuning the kernel for even more power savings?
Actually, RTC interrupts 1024 times a second, system clock 18.2 times a
second, and I'd guess something else bothers the CPU some dozen of times
a second, like keyboard/disk/network/mouse/vga/power/today_is_a_nice_day
and so on. I'd guess masking out the RTC might help a lot, but long time
it was since I last touched a PIC...

Have phun!