P4P800-E Deluxe -- Q-Fan & CHA_FAN

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J

John Blaustein

Using a P4P800-E Deluxe in an Antec SLK3700-BQE case with Antec SL350 PSU.

CPU fan is Zalman 7000A-AlCu.

Case fans:
Rear -- Antec without sensor lead
Front -- Antec SmartCool with sensor lead

The PSU and CPU fans have sensor leads which are connected to the mobo.
ASUS Probe and MBM5 see and monitor these temps and fan speeds.

The front fan (SmartCool) has a lead, but when I connect it to the CHA_FAN
connector, I get erratic readings in ASUS Probe and MBM5 doesn't see this
fan. Having this fan connected to CHA_FAN "screws up" the speed readings of
the other two fans in Probe. (I have the latest version of Probe.)

QUESTIONS:

-- Why am I having trouble when the SmartCool fan is connected to the
CHA_FAN connector? Should that work correctly? Why won't MBM5 recognize
that fan?

-- Antec's Web site says the PSU has SmartPower to sense temps and adjust
the fan speed. The SmartCool case fan also has a built-in sensor and
adjusts speed automatically. If this is the case, should I have Q-Fan
disabled? Will the built-in fan technology conflict with Q-Fan, or make it
unnecessary?

Thank you.

John
 
John Blaustein said:
Using a P4P800-E Deluxe in an Antec SLK3700-BQE case with Antec SL350 PSU.

CPU fan is Zalman 7000A-AlCu.

Case fans:
Rear -- Antec without sensor lead
Front -- Antec SmartCool with sensor lead

The PSU and CPU fans have sensor leads which are connected to the mobo.
ASUS Probe and MBM5 see and monitor these temps and fan speeds.

The front fan (SmartCool) has a lead, but when I connect it to the CHA_FAN
connector, I get erratic readings in ASUS Probe and MBM5 doesn't see this
fan. Having this fan connected to CHA_FAN "screws up" the speed readings
of
the other two fans in Probe. (I have the latest version of Probe.)

QUESTIONS:

-- Why am I having trouble when the SmartCool fan is connected to the
CHA_FAN connector? Should that work correctly? Why won't MBM5 recognize
that fan?

-- Antec's Web site says the PSU has SmartPower to sense temps and adjust
the fan speed. The SmartCool case fan also has a built-in sensor and
adjusts speed automatically. If this is the case, should I have Q-Fan
disabled? Will the built-in fan technology conflict with Q-Fan, or make
it
unnecessary?

Thank you.

John
Click to expand...

Q-Fan only controls the CPU fan RPM.
You do not have to disable Q-Fan.
If a Fan RPM is too low, MBM5 or probe may show a meaningless (very high)
RPM.
But, I have never seen this resulting in all the other RPM being sensed
wrong too!
To make sure nothing is wrong with the chassis fan header, connect your case
fan (that has problems with MBM5) to the PSU fan header instead of the CHA
header and see if that one shows a correct RPM.
 
Navid,

Thank you.

I didn't know that about Q-Fan.

Probe is showing very high (negative, as I recall) numbers, so maybe it's
because the speed is low. I'll have to re-test all of this... perhaps I was
wrong that the other numbers were incorrectly reported in Probe when the
CHA_FAN was connected.

I will try your suggestion of trying the fan lead on the PSU fan header.
I'll report back.

Could the fan's auto-sensing technology conflict with the mobo readings?

John
 
John Blaustein said:
Navid,

Thank you.

I didn't know that about Q-Fan.

Probe is showing very high (negative, as I recall) numbers, so maybe it's
because the speed is low. I'll have to re-test all of this... perhaps I
was
wrong that the other numbers were incorrectly reported in Probe when the
CHA_FAN was connected.

I will try your suggestion of trying the fan lead on the PSU fan header.
I'll report back.

Could the fan's auto-sensing technology conflict with the mobo readings?

John
Click to expand...

The RPM measurement is done by the third wire on the fan. If the fan has
RPM control based on temperature or not, the RPM reading itself should not
be affected, one way or the other.

The fan RPM is adjusted based on its temperature measurement (higher T >
higher RPM; lower T > lower RPM).
Any negative feedback system can become unstable if not designed properly.
Having multiple control systems trying to control the same thing (case
temperature in this case) can add to the possibility of difficulty. But,
you will notice it. Oscillation (instability of the control system), in
this case, will show up as the fan RPM going up and down continuously and
you will hear it. If you do not have that problem, you should be OK.
 
Navid,

OK... here's the scoop...

I did the test you suggested -- connecting the chassis fan lead to the
PWR_FAN header. It worked fine, and reported the same number as when it is
connected to the CHA_FAN header. So, the mobo is fine (I'm glad to report).

As of right now, the PSU lead is connected to PWR_FAN and the front fan lead
is connect to CHA_FAN. Probe is reporting PSU=1259; CHA=1163; CPU=2083.

Since it's all working now, I'm not sure why it wasn't working before, but I
can imagine the chassis fan dropped to below the 600 threshhold and that
triggered the alarm. I may have been wrong in my initial post that the
other numbers were reporting incorrectly.

I tried to lower the CHA_FAN threshhold in Probe, but 600 is the minimum.

When I first boot with both the PWR and CHA leads connected, BIOS reports:
CPU betw 2481 & 2096 (I think Q-Fan kicks in)
CHA 1196 IN RED LETTERS
PWR 1250 IN RED LETTERS

Since Q-Fan only controls the CPU fan, it seems there is no real advantage
to keeping the chassis fan connected to CHA_FAN, other than it's good to
know what it's doing.

By the way, is it OK to connect and disconnect the PWR_FAN and CHA_FAN leads
while the machine is running? Can that damage anything? For testing, it's
a lot easier to move the leads while the machine is running.

John
 
Forgot to ask... how can I get MBM5 to see all three fans -- CPU, PWR and
CHA?

John
 
See below for the comments.

John Blaustein said:
Navid,

OK... here's the scoop...

I did the test you suggested -- connecting the chassis fan lead to the
PWR_FAN header. It worked fine, and reported the same number as when it
is
connected to the CHA_FAN header. So, the mobo is fine (I'm glad to
report).

As of right now, the PSU lead is connected to PWR_FAN and the front fan
lead
is connect to CHA_FAN. Probe is reporting PSU=1259; CHA=1163; CPU=2083.

Since it's all working now, I'm not sure why it wasn't working before, but
I
can imagine the chassis fan dropped to below the 600 threshhold and that
triggered the alarm. I may have been wrong in my initial post that the
other numbers were reporting incorrectly.

I tried to lower the CHA_FAN threshhold in Probe, but 600 is the minimum.

When I first boot with both the PWR and CHA leads connected, BIOS reports:
CPU betw 2481 & 2096 (I think Q-Fan kicks in)
CHA 1196 IN RED LETTERS
PWR 1250 IN RED LETTERS

Since Q-Fan only controls the CPU fan, it seems there is no real advantage
to keeping the chassis fan connected to CHA_FAN, other than it's good to
know what it's doing.
Click to expand...

The alternative is connect it directly to the power supply. Then, MBM5 or
ASUS probe will not be able to monitor the RPM since the third wire will not
be connected to the motherboard.
By the way, is it OK to connect and disconnect the PWR_FAN and CHA_FAN
leads
while the machine is running? Can that damage anything? For testing,
it's
a lot easier to move the leads while the machine is running.
Click to expand...

I don't know. Although, I have done that too.
 
John Blaustein said:
Forgot to ask... how can I get MBM5 to see all three fans -- CPU, PWR and
CHA?

John
Click to expand...

Right click on the MBM5 icon in the taskbar and select "settings".
Click on "Fans".
Click on "Visual".
Choose a fan number.
Choose a board sensor.
Check "Display this fan in the dashboard screen".
Click apply.

You may have try different sensors to find the one you are looking for.
 
OK.

Thanks so much for all of your help, Navid! I think I'm in good shape now.

John
 
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