[ltp] X61 or X61s (loud fan)

[Henrique de Moraes Holschuh]

On Wed, 20 Aug 2008, Christian Fromme wrote:
> I am running 2.6.25-686 from the Lenny archive. I dont think it's the CPU
> heat. CPU stays around 40-50 degree most of the time. The wireless card
> seems to be the cause for the heat at the right handrest. The X61s has a
> different wireless card. Maybe it's cooler.

Something people never tell you is that AGN cards have either two or three
radios that need to operate at the same time, and that really means a lot
more heat than ABG or BG cards :)

And there are at least three different versions of the WiFi hardware on
recent thinkpads (something by Atheros, plus Intel 3xxx and 4xxx), and they
all have different heat output profiles.

> > The X61s should be a LOT more silent (but it has a less powerful CPU)...
> > but you might have a X61 that has an especially bad fan (or badly seated
> > thermal sink), and replacing them might be enough (instead of replacing
> > the
> > entire laptop).   Ask your supplier about it.
> 
> I am a bit drawn forward and backward. Some people are reporting that the
> X61 is *very* quiet to them. Maybe it's just my crappy fan. It seems like
> you never know the machine until it sits in front of you, whatever some
> tests and reports say.

Ignore any reports of "cool" or "hot" or "noisy" that do not disclose which
CPU (and GPU) and how much RAM the user has in the box when you are trying
to decide whether a notebook will be more friendly to your lap or ears.
And, as you found out already, WiFi at full blast can have a lot of impact
as well.  Same goes for the HD, but most of the time people measure things
with a quiet HD usage profile, which means it is not heating up too much.

> > The X60s and X61s have ultra-low-power CPUs, they really draw less power,
> > and therefore they have less heat buildup.  They are supposed to be more
> > silent because of that (unless the fan or thermal sink is bad in a
> > particular X60s/X61s).
> 
> The CPU is the main reason why I initially decided to go with the X61
> instead of the X61s. 2,4GHz compared to max. 1.8GHz is an argument for me.
> But working on a loud and hot machine isn't fun either. :-/

The X60 and X61 will limit the CPU to around 1GHz when it starts heating,
and the reports we get in LKML and linux-acpi (because the current breakage
that instead of limiting the CPU speed, lets it heat up until it shuts down
to prevent damage) shows that it happens far too often.

OTOH, we have some reports from users that never see their X60 get hot
enough to trigger the 1GHz limitiation, even when running CPUburn.  I don't
recall if we have any such positive reports for the X61.

So, really, don't count on those 2.4GHz too much.  You may not have them all
the time, and we have no idea at all if that's because of heatsink problems,
or by design (e.g. affects only the models with fairly powerful CPUs).

And, of course, this all depends on how hot it is where you're using your
laptop...  People working somewhere at 10°C really should not be comparing
their laptop's thermal performance with people who are working at 28°C.  But
neither side ever recalls that they should disclose THAT information when
tossing comments around...

-- 
  "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