>>>>> "Benjamin" == Benjamin Herrenschmidt <benh@mipsys.com> writes:

    Benjamin> Are you sure you really switched the speed and didn't just
    Benjamin> change the _reported_ speed ?

    Benjamin> I found no OF code on this machine to do the actual speed
    Benjamin> switch, I'm currently trying to figure out how to acheive it in
    Benjamin> software.

    Benjamin> Ben.

Yes, the difference between 667mhz and 800mhz is VAST -- so much so that after
I issued the hack and tested compiles it was obvious the machine was running
at a faster speed.  Noticed by time and heat (heh).

Titanium G4 Quicksilver 2002/DVI (aka Rev D) supports a power-saving mode
noted by the floor and ceiling of 667MHz and 800MHz.  "force-reduced-speed"
is either 0 or 1.  MacOSX does things strangely here as I've heard reports
prior to this hack that some users that dual boot a *BSD with OSX have
reported that their CPU erratically flips between the two MHz's.  Sometimes
they boot into BSD at 667, sometimes 800.  I don't know OSX very well but
I presume the software hacks for affecting change on the OpenFirmware are
coming from the closed source portion of the OS.

Benjamin, perhaps your particular tibook does not support the power-saver
mode.  I know Apple did not put this feature in all models, but I'd be
surprised if at least Rev.C doesn't have it.

If you can't trust what OpenFirmware tells you, what can you trust?
The processor is reported to be running as 0x2faf0800.

My advice is to perform the hack and test yourself.  The compile time
differences only slap you in the face.

-- 
Mark Grimes <mark@openbsd.org>
The OpenBSD Project