- Does the Pentium M Processor indirectly control fan speed (laptop)
- Posted by Sanjay Punjab on January 21st, 2004
I own a fujitsu lifebook and the fan seems to have a life of its own.
Turning on and off randomly and racing periodically. It is hard to
explain, but the operating is erratic and my friend's identical laptop
does not suffer from this problem. The laptop has a Pentium M
processor. Fujitsu already replaced the motherboard (including CPU)
and the fan & heatsink, but still the problem exists. I am wondering
if the problem could be the hard drive, especially when the erratic
operation seems to coincide with hard drive operations.
The hard drive has that new S.M.A.R.T. interface that reports
temperature. I am wondering if the Pentium M processor is giving a
false signal to the fan controller chip based on faulty temperature
data from the hard drive via the S.M.A.R.T. interface.
I would appreciate any info on this. Thanks
- Posted by Richard Crowley on January 21st, 2004
"Sanjay Punjab" wrote ...
The processor (Pentium or whatever) only does what it is
told by the people who wrote the BIOS code, and the BIOS
does what it thinks is best based on the information it thinks
it is getting from the temperature sensors, etc. Seems unlikely
that they would run what is essentially the CPU fan based on
heat information from the hard drive, but maybe it is designed
to provide cooling to both?
Is this really a serious problem? What do Fujitsu say? If they
have already replaced the mobo/CPU I'd assume that you would
either have to live with it or sell/trade it if it really bugs you.
- Posted by H. Dziardziel on January 21st, 2004
On 20 Jan 2004 22:40:35 -0800, techman41973@yahoo.com (Sanjay
Punjab) wrote:
If your friend's is identical including the drive, peripherals and
O/S then it must be application or usage related i.e location,
ambient temperature, ventilation etc. ACPI power management used
in all recent laptops can cause unpredicatble fan activity/results
if the O/S is not that laptop model vendor supplied or supported
-- read Windows (probably per some sticker too).
- Posted by Alexei Boukirev on January 21st, 2004
techman41973@yahoo.com (Sanjay Punjab) wrote in
news:e8fde247.0401202240.3177967b@posting.google.c om:
On my Acer TravelMate 800 (Pentium-M) I noticed that fan activity depends
not on CPU temperature but on CPU activity/load. For example, using
scanner on USB raises CPU load during scan, and that kicks fan on
immediately. This is stupid design from manufacturer, but I learned to
live with it.
Alexei
- Posted by Richard Crowley on January 21st, 2004
"Alexei Boukirev" wrote in message
Well, actually CPU temperature depends on CPU
activity/load. Especially in a portable environment
where pieces are slowed/shut down when not in use
to preserve battery life.
Not clear why this seems "stupid" to you? Would you
rather that it run at full speed/power all the time? Suck
the battery life for nothing? Run the fan all the time? Why?
I see the same effect in my big tower machine at home
that I use for editing video. As soon as I start rendering
DV, I can hear the CPU fan speed increase. When it
slows back down, I know it is done.
- Posted by Alexei Boukirev on January 21st, 2004
"Richard Crowley" <rcrowley7@xprt.net> wrote in news:100t4hadcv0b061
@corp.supernews.com:
It does, but not directly. Short rare spikes of high activity do not raise
temperature enough that turning fan on should be required. Yet, TM800
turns on fan each and every time.
See above.
Alexei
- Posted by Robert Myers on January 21st, 2004
On Wed, 21 Jan 2004 05:26:24 -0800, "Richard Crowley"
<rcrowley7@xprt.net> wrote:
Period. And it makes no sense to run the fan more than necessary. Do
you and your friend use the laptop identically? Do you run the same
programs, always having it resting on a hard surface so that vents are
not randomly blocked, say, by sitting in your lap? How attentive is
your friend to his computer? Does his "No, my computer never does
that" really mean it happens in situations where there are enough
distractions that he would never notice? Sit the two computers side
by side and perform a controlled experiment, if his computer really
*is* identical (same GHz, same memory, same disk)? No, you already
said the disk drives are different, and yes, disk operation can affect
the fan.
Nice of Fujitsu to replace all that stuff. No big surprise that it
didn't change anything. Find something else to worry about.
RM
Seems unlikely
- Posted by Andre on January 21st, 2004
techman41973@yahoo.com (Sanjay Punjab) wrote in message news:<e8fde247.0401202240.3177967b@posting.google. com>...
I owned a Toshiba laptop, and a BKPW Note Pro like this, its a
"feature" that keeps the processor at the same temperature while
maximising battery life (reducing the fan speed during low CPU usage,
and increasing it when the CPU is being thrashed, such as a lot of
3D).
You might try looking in the BIOS for anything like "Fan mode
settings" or similar, sometimes they give you the option of turning
off the demand based fan speed.
-A
- Posted by Ralph Wade Phillips on January 22nd, 2004
Howdy!
"Alexei Boukirev" <aboukirev@blah.ameritech.net> wrote in message
news:Xns947770A35796Caboukirevblahamerite@216.196. 105.138...
So it should wait to turn it on? The fan control logic doesn't know
how long your task will run - and it could easily be a design criteria to
keep the temp down as low as possible concurrent with decent battery life.
Doesn't sound so bad to me,honestly.
RwP
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- Posted by Alexei Boukirev on January 22nd, 2004
"Ralph Wade Phillips" <ralphp@techie.com> wrote in
news:400f55a0_2@127.0.0.1:
It should turn on when temperature reaches certain level.
To prove my point let's see a different situation - medium CPU load for a
long time raises temperature significantly (much higher than after that
short spike of load), yet fan does not turn on. Is that a good design?
No way.
The idea is to keep temperature down, so that should be a controlled
parameter. You do not control engine temperature and cooling by
measuring how fast the car goes, you do it with a thermal sensor.
Alexei
- Posted by Richard Crowley on January 22nd, 2004
"Alexei Boukirev" wrote ...
It sounds like that is exactly what it is trying to do.
That was the "state of the art" solution from 100 years ago.
Computers (and even vehicles!) are much more sophisticated
than that these days. They can anticipate need, and even "learn"
usage patterns. The machines are getting smarter than us whether
we like it or not! :-)
- Posted by Alexei Boukirev on January 22nd, 2004
"Richard Crowley" <rcrowley7@xprt.net> wrote in news:100vs57445lvs98
@corp.supernews.com:
This reminds me of Microsoft Word, which sometimes keeps capitalising some
words whether I like it or not :-) I get really frustrated when I'm forced
to go back and change letter case to what it should be (what I originally
entered). "Smartness" have both good and bad sides.
Unfortunatly with some laptops, when you enter BIOS, you only have a choice
to let it control fan in a "smart" way or have fan always on. What I want
is a choice to control fan in "normal" way, i.e. depending on CPU
temperature (well, maybe add ambient temperature influence there).
Alexei
- Posted by Richard Crowley on January 23rd, 2004
"Alexei Boukirev" wrote ...
Mostly negative IMO. The newer versions of Windows
seem to be HARD WIRED to paste WITH formatting and
it is driving me completely up the wall. I am forced to go
through a menu item just to get plain old-fashioned "dumb"
paste. And sometimes the option isn't available at all! 8-{
