Powering a fan from the motherboard?

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A Little Bit

I have a 12 Volt, 0.13 Amp 8cm fan here (recovered from a power supply, I would
imagine) that has the right plug on it to run it from my P4P800 Deluxe
motherboard. Does this fan draw more current than would be good for the
motherboard?

Thanks for any replies.
 
I have a 12 Volt, 0.13 Amp 8cm fan here (recovered from a power supply,
I would imagine) that has the right plug on it to run it from my P4P800
Deluxe motherboard. Does this fan draw more current than would be good
for the motherboard?

Thanks for any replies.
Click to expand...

My Asus mobo manual says that the mobo will support 350ma (4.2 watt) fans off
the chassis fan header. 12 volt x .13 amp=1.56 watts, which falls easily
within the limit.
 
A 2-wire type fan has power supplied only, and the power is connected not to
the mobo, but via a molex connector to the wires that come directly from
the power supply, on the same power chain that powers the CD/HD/Floppy. If
you have a connector for CHA_FAN on the mobo it is probably a 3-wire
type,which allows mionitoring of the fans speed as well as supplying the
power, all on the same 3-pin plug, at the mobo.

I am going to try to get to the bottom of the fan speed monitoring problem
with respect to variable speed fan type options. I need to buy a fan with
3-wire; I've got a couple 2-wire already. They are cheap. For instance,
Vantec has an 80mm that has th efollowing specs: 23.8-41.6 cfm,
25.5-37.5dBA, 1950-3400 RPM. These are the things you have to look for
because Asus has alluded to Q-fan as "smart, adjusts the fan speeds,
according to system loading, to ensure quiet, cool and efficient operation.
to needs". I don't know if this is just alarm/ set it yourself, etc...
Probably hocus pocus. There is nothing on the web site I can find. I could
read it a thousand times and not know the first thing about what they're
talking about. Anybody got any info about this?

My post in this respect will soon be under the sender kgs. Just hope it
gets more response than my other posts.
 
A 2-wire type fan has power supplied only, and the power is connected
not to the mobo, but via a molex connector to the wires that come
directly from the power supply, on the same power chain that powers the
CD/HD/Floppy. If you have a connector for CHA_FAN on the mobo it is
probably a 3-wire type,which allows mionitoring of the fans speed as
well as supplying the power, all on the same 3-pin plug, at the mobo.

I am going to try to get to the bottom of the fan speed monitoring
problem with respect to variable speed fan type options. I need to buy
a fan with 3-wire; I've got a couple 2-wire already. They are cheap.
For instance, Vantec has an 80mm that has th efollowing specs: 23.8-41.6
cfm, 25.5-37.5dBA, 1950-3400 RPM. These are the things you have to look
for because Asus has alluded to Q-fan as "smart, adjusts the fan speeds,
according to system loading, to ensure quiet, cool and efficient
operation. to needs". I don't know if this is just alarm/ set it
yourself, etc... Probably hocus pocus. There is nothing on the web site
I can find. I could read it a thousand times and not know the first
thing about what they're talking about. Anybody got any info about
this?

My post in this respect will soon be under the sender kgs. Just hope it
gets more response than my other posts.
Click to expand...

I have a Thermaltake 80mm Smart Case II Fan in the front.
It is 3 wire with a temp probe and a rheostat
You have 3 installation options
No probe or rheo and it runs at full speed 4800 RPM
Rheo controlled
Probe controlled; 1300 to 4800 RPM automatically
I attached the probe to one of the vid card ram chips. Fire up a game and
the fan spins up pretty smartly.
Specs:
1300 rpm at 20°C 4800 rpm at 55°C
Max. Air Flow 20.55 CFM at 1300rpm 75.7 CFM at 4800rpm
Air Pressure 1.45mm H2O at 1300rpm 8.43mm H2O at 4800rpm
Noise 17 dB at 1300 rpm 48 dB at 4800 rpm
Bearing Type Two Ball Bearing
Life Time 50,000 hours
Connector 3 PIN
 
This just shows a comparison of fan specs. I want to know what monitoring
is done by asus, and what the result is when selecting a different fan.
Fans have differnt cfms/rpms/dBAs/VAs, and POSSIBLY the ability to monitor
and change these values. One fan will not behave the same as another. p2-27
of the p2c800-e deluxe manual says the "3-pin CPU_FAN, PWR_FAN, CHA_FAN fan
connectors support cooling fans of 350mA~740mA (8.88Wmax.) or a total of
1A~2.22A (26.64W max.) at +12V". I don't know if is the variable
output(controllable range), or if any value in between is the max fan rating
to connect, and if it makes a diffrence if the fan types allows supports
monitoring and adjustment, or if all 3-wire fans do all of the above. What
about adding other built-in fan functionality inline with the 3-pin at th
emobo. I want cool, but I don't neccesarily want to bypass an already
existing technology, especially since I am ignorant as to the cause and
effects, and needs. What about attaching a reostat & tach inline on the
CHA_FAN jack on the mobo.

Can you split the fan load at the CHA-FAN connector, (and monitor) for (i)
output fan @ rear top, and (ii) input fan @ front (don't get me started
about HD cooling in the process).

I'm just upgrading to this mobo and soon will get el4200 ram, and a 2.4C-~C
processor, and will probably want to see what it can do, in comparison to
published results. Don't know what heat to expect.
 
.....One fan will not behave the same as another. p2-27
of the p2c800-e deluxe manual says the "3-pin CPU_FAN, PWR_FAN, CHA_FAN fan
connectors support cooling fans of 350mA~740mA (8.88Wmax.) or a total of
1A~2.22A (26.64W max.) at +12V". I don't know if is the variable
output(controllable range), or if any value in between is the max fan rating
to connect, and if it makes a diffrence if the fan types allows supports
monitoring and adjustment, or if all 3-wire fans do all of the above....
 
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