P4C800E Dlx and Fan Speed Control ???

  • Thread starter Thread starter Walt
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Walt

I can get both BIOS's own Q-FAN, and the SpeedFan Windows
application to successfully vary the speed of the CPU fan.

However, I can't get either to vary the speed of either
the power supply (PWR) or case (CHA) fans.

Has anyone else worked with fan speed control with this
motherboard? If so, how successful have you been in
controlling the three fans (CPU,PWR,CHA) ???

I am going to be pretty disappointed if ASUS once again
screwed up their MB wiring and fan speed control isn't
fully possible. ASUS already got me once with NO fan
speed control on my old P4B266-C. :(
 
You need to disable Q-Fan in Bios, and in SpeedFan you have to go
under the 20% limit to notice a change in noise/rpm... So on...

hand

Daniel
 
I can get both BIOS's own Q-FAN, and the SpeedFan Windows
application to successfully vary the speed of the CPU fan.

However, I can't get either to vary the speed of either
the power supply (PWR) or case (CHA) fans.

Has anyone else worked with fan speed control with this
motherboard? If so, how successful have you been in
controlling the three fans (CPU,PWR,CHA) ???

I am going to be pretty disappointed if ASUS once again
screwed up their MB wiring and fan speed control isn't
fully possible. ASUS already got me once with NO fan
speed control on my old P4B266-C. :(
Click to expand...

Q-Fan is intended to control the CPU fan, and uses the
CPU temperature for feedback about the setting to use.

I just downloaded the W83627THF Winbond datasheet, and
this chip has three fan speed controllers. They are not
the normal PWM (pulse width modulation) controls, but are
a simple 0-5V level instead. This requires a buffer circuit
to drive the 12V fan, and those cost a few extra pennies.

http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/627hf.pdf

I only see a transistor around the CPU fan header. (The op
amp to drive the transistor could be housed in a quad device
elsewhere on the motherboard.) The other fan headers don't
seem to have anything like that. Without a power transistor
of some sort, it won't be adjustable. (And, the analog
control method is better for the fan, but kicks off more
heat from the power transistor itself. PWM solutions
run cooler.)

As for the transistor next to the CPU, when the fan speed is
low, the transistor will have 5V across it, leaving 7V for
the fan. At a 200ma current level, the transistor dissipates
5V*0.2A = 1W, and 1W is a reasonable estimate for a safe power
limit for an SMT device with 1 sq inch of copper for cooling.
The manual gives some higher numbers for this circuit, and
the higher numbers might be more appropriate for a PWM fan
controller (as a PWM'ed pass transistor is saturated or open
circuit, and is controlled with a square wave signal). I suspect
the blurb in the manual, about how much current the CPU fan
can handle, is a copy-paste error. Disabling QFan would cause
the pass transistor to saturate, reducing the voltage drop
and the power dissipated, as would setting the fan to a
higher speed. The worst condition for the pass transistor
is when the fan speed is low. (Stick your finger on it and see
how hot it gets :-)

HTH,
Paul
 
Yes, I had Q-Fan disabled when I tried SpeedFan.

I thought the default manual speed controls in SpeedFan always worked?
 
Thanks Paul for taking the time to check this out, and post
your results!!!

I guess I just have to accept that once again, have ended up
with an ASUS board which has limited or no fan speed control.
Your info, at least, means I don't have to keep searching for
"better" software. No software will be able to control
the other fans. :(

It is interesting that ASUS features (pushes) Q-Fan as a way to
greatly reduce the fan noise in a PC. However, just controlling
the CPU fan, and NOT the case fans nor the power supply fans
will do very little to reduce the overall fan noise. Matter
of fact, I bet one can't even tell, noise wise, when JUST
the CPU fan is reduced in speed by 20%.

Ah, it seems that I have been spoiled by the old P3B-F which
allows me to control ALL the fans with SpeedFan. :)
 
Walt said:
Thanks Paul for taking the time to check this out, and post
your results!!!

I guess I just have to accept that once again, have ended up
with an ASUS board which has limited or no fan speed control.
Your info, at least, means I don't have to keep searching for
"better" software. No software will be able to control
the other fans. :(

It is interesting that ASUS features (pushes) Q-Fan as a way to
greatly reduce the fan noise in a PC. However, just controlling
the CPU fan, and NOT the case fans nor the power supply fans
will do very little to reduce the overall fan noise. Matter
of fact, I bet one can't even tell, noise wise, when JUST
the CPU fan is reduced in speed by 20%.

Ah, it seems that I have been spoiled by the old P3B-F which
allows me to control ALL the fans with SpeedFan. :)
Click to expand...
Maybe a bit off topic, Walt, but as you are using SpeedFan, do you know if
it's possible to control the fanspeed of an Asus Radeon 9600 XT with this
piece of software? For the reason of asking you this, please take a look at
my other post about Asus Smartdoctor on Win XP Prof. in this NG today.

Jan
 
Walt said:
All I can offer, is to suggest check out SpeedFan's website at
http://www.almico.com/speedfan.php

BTW, I am using Win XP Pro SP1 too, and had no problem installing
SpeedFan.
Click to expand...
Thanks Walt, I just hoped you could tell me if Speedfan could do the job for
the Asus 9600 XT before bothering to install it, because I use a Zalman CPU
cooler and a Thermaltake case and the two of them give me the opportunity to
control the fans hardwarewise. BTW, my install-problems are not with
Speedfan, but with Asus Smartdoctor.

Jan
 
Thanks Paul for taking the time to check this out, and post
your results!!!

I guess I just have to accept that once again, have ended up
with an ASUS board which has limited or no fan speed control.
Your info, at least, means I don't have to keep searching for
"better" software. No software will be able to control
the other fans. :(

It is interesting that ASUS features (pushes) Q-Fan as a way to
greatly reduce the fan noise in a PC. However, just controlling
the CPU fan, and NOT the case fans nor the power supply fans
will do very little to reduce the overall fan noise. Matter
of fact, I bet one can't even tell, noise wise, when JUST
the CPU fan is reduced in speed by 20%.

Ah, it seems that I have been spoiled by the old P3B-F which
allows me to control ALL the fans with SpeedFan. :)
Click to expand...

I would have recommended a drive bay fan controller, but with
my lousy searching skills, all I've found so far, are the
manual style (Nexus) controllers. I thought there was at least
one product out there, that has thermistors for controlling
case fans.

The most important thing to provide air flow for in the computer,
is for the disk drives. They have the tightest environmental
requirements, and it would be best if inlet air is drawn across
them without mixing with the other case air. The rest of the
components can safely take a lot more heat, relatively speaking.

I just recently bought a P4C800E Deluxe (as I'm not interested
in LGA775 or PCI Express or processors with large DC leakage
currents that waste power not related to computing). I checked
with an ohmmeter, and the two other fan headers have their
+12V pin connected directly to the +12V pin on the ATX20 pin
connector. It would seem there is no controlling device in that
path.

If Q-Fan and Speedfan attempt to control the Winbond chip at
the same time, I think you can see there would be chaos. Only
one program should be writing to the fan control register at
a time, if you want consistent results. Also, from a monitoring
perspective, only one monitoring program (Asus Probe, Motherboard
Monitor, Speedfan etc) should be running at a time, as the OS
provides no semaphore for controlling access to the serial
SMBUS. That bus runs so slow (10KHz?), it is possible for one
monitor program to kick off a "read" op on the serial bus, and
then the OS can schedule the execution of the other monitor
program, which might just be about to do the same thing. An
interrupted read op, results in garbage data and a "spike" in
the smoothed results. (My theory is, it is not entirely possible
to eliminate this fully, as the BIOS is reading the registers all
the time too ?)

Paul
 
I, too, have only found the manual fan speed controls. I would
be very interested in one that worked by sensing temps, and
automatically adjusted the fan speeds appropriately. If someone
knows of any, please post a reference here!

Thanks for verifying that Power Supply (PWR) and the Case
(CHA) fan power connectors are, indeed, connected directly
to the +12v and thus can't be controlled. Again, I am not real
happy with ASUS being so cheap. Plus, ASUS advertises that
this MB, with Q-FAN running, can dramatically reduce system fan
noise. Without being control the speed of either the Power Supply
fan nor the any of the Case fans, it simply can't. :(
 
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