Re: [tlug] NEC Laptop

["Lyle (Hiroshi) Saxon" <ronfaxon@example.com>]

Josh Glover wrote:

>>[LHS] One other issue, and this is more serious I think.  Running Linux,
>>the machine's cooling fan never runs!
>>
>
>This quite likely has something to do with ACPI. Try searching Google
>for something like: acpi linux "fan doesn't run"
>
>I found the following link which may be helpful:
>
>http://www.naos.co.nz/hardware/laptop/acer-361evi/x94.html#AEN213
>
>You might try disabling ACPI and APM in the kernel, unless it is
>already, in which case try *enabling* it.
>
>
I'm still looking into APM, and thanks to the link may have figured out 
what is what with the cooling fan:

After reading this from the article:
"The internal fans appear to be managed by the hardware. I configured 
the laptop to run in "battery optimizing" mode, even though I normally 
run it on the mains. One side effect of this is that it normally steps 
down to 700MHz (from the full 1GHz) because very little I do requires 
even that much CPU power. This has the nice effect of keeping the CPU 
cooler, which means that the CPU fan doesn't run much at all...."

- I think I've begun to get a picture of how the machine is working overall:

1) In comparing my Linux box with a W2K box (and an old always-off-line 
W98 machine), I have found the default settings for Linux (SuSE 9.0/9.1) 
keep the HDD spinning non-stop when the box is powered up.  I briefly 
set power management (on a desktop) to minimize power consumption, which 
enabled the hard drive to take a rest from time to time (the way I have 
the W-boxes set to run), but the performance penalty was more than I was 
willing to put up with, so I reset it back to "Maximum Performance". - I 
mention this, because it suddenly occurs tome that the main cause of the 
heat in the NEC laptop isn't the CPU, but rather the hard drive.

2) While I hadn't observed any operation of the cooling fan under Linux 
when I sent my last e-mail, since then, I have observed it very briefly 
running when logging in a new user right after logging out another one.

3) The cooling fan of the laptop is on the left rear side, which appears 
to be where the HDD is - so I now presume that it is triggered by CPU 
activity (do the sensors for CPUs monitor actual heat generated, or just 
percent of CPU activity?), and due to Linux more skillfully utilizing 
the processor, the fan is hardly ever activated, but the always-on hard 
drive is what is generating the high temperatures.

So... if that's indeed the case, I suppose there's nothing to worry 
about - laptop hard drives are designed to operate under very hot 
conditions I think.  Still, considering the heat generated 
(uncomfortably hot to the touch, but no billowing steam or third degree 
burns at least), it would probably be better if the cooling fan ran more 
often to remove some of the HDD heat.  On the other hand... the case 
being so hot is evidence that it is heat-sinking to the case, so maybe 
all is right with the world and many happy computing 
hours/days/weeks/years(?) await?

Thanks for the tips!

Lyle