That is, /proc/cpuinfo says "cpu MHz" is 121 rather than 450 (or 448).

The only adverse effect I've noticed is that the time of day clock under DOSEMU runs 4x fast (it's getting ticks at 448MHz and thinks they're coming at 121MHz).

I haven't yet figured out what triggers this. My current suspicion is that it has to do with the order of events when coming out of suspend or hibernation.

2000 Apr 19 - I think what must be happening is that the power management actually slows the clock down under certain conditions and Linux is picking up on this. I used tpctl --pmb to set the battery power management mode to high and haven't seen the problem since.

Presumably one could keep the mode something other than high most of the time, switch to high if the problem cropped up, suspend the machine and awaken it, and things would be OK. (One might need to restart certain applications to make sure they know the real clock rate.) I haven't tested this hypothesis though...

2000 Jul 15 - I received the following email:

The CPU speed is calculated only once by the kernel a boot time. Read the bogomips documentation.

If you are on battery power with power saving on at boot time, the the kernel calculates the "slow" speed and uses it from there on.