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Two SpeedStep issues



Hello,

I have two machines exposing more or less unexpected behaviour with respect to 
SpeedStep (both on 5.0_STABLE and HEAD).

One is equipped with a Core2Duo E8200. NetBSD reports 800 700 600
as the frequencies available. I think this should be 2666, 2333
and 2000 or similar. I don't know whether this makes a practical
difference, but it irritates me a little. A snippet from its dmesg
(including timecounter info; you never know):

timecounter: Timecounters tick every 10.000 msec
timecounter: Timecounter "i8254" frequency 1193182 Hz quality 100
MICRO-STAR INTERNATIONAL CO.,LTD MS-7519 (1.0)
mainbus0 (root)
cpu0 at mainbus0 apid 0: Intel 686-class, 2673MHz, id 0x10676
cpu0: Enhanced SpeedStep (1212 mV) 800 MHz
cpu0: Enhanced SpeedStep frequencies available (MHz): 800 700 600
cpu1 at mainbus0 apid 1: Intel 686-class, 2673MHz, id 0x10676
...
timecounter: Timecounter "ACPI-Safe" frequency 3579545 Hz quality 900

I'm including the timecounter info because it seems possible to me
that this is somehow timing-related, as I once tried a DEBUG kernel
and the CPUs then got reported as being clocked at little below
4 GHz...

The other one, a ThinkPad R50e, is equipped with a Celeron M 1400.
I didn't really expect it to have SpeedStep support at all, but
OpenBSD (in practice) claims to lower its frequency to as low as
367 MHz, claiming the battery would then last about 6 hours. I
didn't test whether this actually works, apart from waiting quite
a while for the fan to turn down, which it didn't, suggesting to
me that OpenBSD was not quite telling the truth, but am curious
whether it is considered possible, and if so, what changes would
be necessary to achieve this on NetBSD.

I'd be thankful for any hints.

TIA,

Dennis den Brok


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