When it's actually idle, it's completely stopped -- 0 MHz; since it takes more total power to compute a given workload at 125MHz than 250MHz, 125MHz idle is likely counterproductive,l and definitely makes the system less responsive.

In fact many of us are running with a 500MHz minimum (again, only when it is actually processing -- it drops to 0 when truly idle), and thinking we get better battery life than the stock 250Mhz. Of course, battery life under real-world use is tough to benchmark, but on the bright side, it doesn't make much difference, no matter who's right.

Of course, either way, you will increase battery life by dialing down the voltage from stock (which has to be stable for all CPUs) to the minimum required for your CPU. Typically, you can run 900MHz or so on the same voltage the stock kernel uses for 600MHz, and when you're running at 600MHz, use substantially less -- this effect is generally bigger than whatever difference there is among minimum frequencies, so you're practically guaranteed increased battery life.


Lehto's does offer improved compatibility with kernel modules built for the stock kernel, but AFAIK the only place this is an issue right now is with fcam, and titan already has a preliminary release for that

I strongly recommend titan's kernel, because you can adjust all these parameters at run time:

• minimum clock
• maximum clock
• and for each clock speed
  • enable/disable (to reduce excessive stepping, or if your hardware has issues at certain frequencies)
  • DSP clock
  • voltage

A complete voltage profile tuned at each step for your specific hardware is basically guaranteed to save power vs. picking the lowest non-crashing from several complete profiles.

Of course, be sure to back up your data before you start -- there's a non-negligible risk of corrupting a filesystem and trashing your system when you're initially tuning voltages (whether by selecting amongst entire profiles, or tuning individual frequencies); once you've established a fully stable profile, no worries.