[ltp] frequencies, throttling

Henrique de Moraes Holschuh linux-thinkpad@linux-thinkpad.org
Mon, 5 Mar 2007 12:20:02 -0300


On Mon, 05 Mar 2007, Damien Challet wrote:
> Therefore if you use a laptop as a gateway in a very silent environment, 
> throttling may be a good idea if the fan tends to kick in (it makes 2-3C 
> difference in my experience). Otherwise, forget about it.

Only if the CPU is crap/very old, or something else is screwing up with its
ability to enter deep C states (like the el-crap UHCI chip, disable it by
removing uhci-hcd).

A proper mobile CPU (Pentium-M and friends) that is correctly supported will
stay most of the time at its lowest core clock AND with a lot of its
internal circuitry powered off or halted (C3 state).  That beats throttling
in diminishing the power dissipation by a large margin.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh