Running two 120mm fans off one 3 pin header?
- Thread starter NeilF
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as long as they arent delta's or something similar... each header on that MB from memory can take 24 watts and 2amps, for a total of 84 watts and 7amps across all headers (would double check this in the manual!) so as long as the fans total requirements dont exceed that you are fine.
They're these - http://www.hipergroup.com/products.php?lv=3&cate=15&type=16&pid=59&w=1024&h=612
Which are listed as input current 0.26 A (MAX.), so I should easily be able to run 2 or 3 off a single header? And all of them would run at full speed?
Ta!
BTW!! over 4ghz with a Q6600 what FSB/multiplier?
447 x 9
Soldato
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Fine - I'm running 3 x yate loon 120mm fans from my CPU header, so the speed varies with CPU temp.
Fine - I'm running 3 x yate loon 120mm fans from my CPU header, so the speed varies with CPU temp.
Can't do that as the stupid Asus P5Q Pro motherboard can't vary the speed of 3pin fans! (on the CPU header).
Infact although it has 3x3pin headers (2x'chassis' and one 'power') and a 4pin cpu header, it can only adjust 3 pin fans on two of them, and even then they are on the same loop. So you can only control two headers to the same rate.
I will at the very least have to connect my CPU fan to a chassis fan to vary it according to CPU temp (with speedfan)
The CPU header speeds up and slows down the CPU heatsink fan depending on the CPU temp, so it sounds like Mike has the pc thinking his rad fans are the cpu fan. Therefore cooling the rad more or less dependant on the cpu temp
EDIT: Though it's 4 pin and not 3
EDIT: Though it's 4 pin and not 3
Soldato
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I've just got the yate loons plugged to the 4 pin cpu header, as long as my fan speed is set to "legacy" and "voltage" then the speed goes between 400rpm and 800rpm depending on how hot the q6600 is.Can't do that as the stupid Asus P5Q Pro motherboard can't vary the speed of 3pin fans! (on the CPU header).
Infact although it has 3x3pin headers (2x'chassis' and one 'power') and a 4pin cpu header, it can only adjust 3 pin fans on two of them, and even then they are on the same loop. So you can only control two headers to the same rate.
I will at the very least have to connect my CPU fan to a chassis fan to vary it according to CPU temp (with speedfan)
You may be able to do this on the Asus, but I haven't used an Asus board since my P5B died for no reason.
I also cannot use speedfan as I also run Linux and OSX on my rig - it needs to be BIOS controlled.
I've just got the yate loons plugged to the 4 pin cpu header, as long as my fan speed is set to "legacy" and "voltage" then the speed goes between 400rpm and 800rpm depending on how hot the q6600 is.
You may be able to do this on the Asus, but I haven't used an Asus board since my P5B died for no reason.
I also cannot use speedfan as I also run Linux and OSX on my rig - it needs to be BIOS controlled.
Think the CPU fan is 4 pin PWM or nothing! Seems daft you can't just alternatively voltage it like all the other headers
Soldato
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I thought the 4 pin connector wouldn't work also, but the 4th pin is for the PWM signal, so isn't really needed anyway.Think the CPU fan is 4 pin PWM or nothing! Seems daft you can't just alternatively voltage it like all the other headers
It wasn't until I went thru the manual I found that 3 pin fans work fine with the 4 pin connector. It might be worth experimenting with your Asus?
That said, the only way I can very the voltage on the other headers is with speedfan, but I've soldered in some resistors with my case fans so they run slow enough even with the motherboard headers chucking out 12v.
I thought the 4 pin connector wouldn't work also, but the 4th pin is for the PWM signal, so isn't really needed anyway.
It wasn't until I went thru the manual I found that 3 pin fans work fine with the 4 pin connector. It might be worth experimenting with your Asus?
That said, the only way I can very the voltage on the other headers is with speedfan, but I've soldered in some resistors with my case fans so they run slow enough even with the motherboard headers chucking out 12v.
A 3pin fan plugged into the 4pin header just means it at 100% all the time. I can find no way in the BIOS or Speedfan to control a 3pin fan on the CPU 4pin header
Soldato
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Just seen your post - yep all my yate loon's are bolted to a 120.3 rad... I the speed control works well, while my case fans just run at 500rpm no matter what the CPU temp is.The CPU header speeds up and slows down the CPU heatsink fan depending on the CPU temp, so it sounds like Mike has the pc thinking his rad fans are the cpu fan. Therefore cooling the rad more or less dependant on the cpu temp
EDIT: Though it's 4 pin and not 3
Ahh, I see...A 3pin fan plugged into the 4pin header just means it at 100% all the time. I can find no way in the BIOS or Speedfan to control a 3pin fan on the CPU 4pin header
I guess I'm just lucky my motherboard is ok with 3 pin fans then... It does seem strange tho, I'm running 2 systems, both with 3 pin fans up to the 4pin CPU header, and speed control works fine. On is using a Gigabyte p965 ds3 (aircooled) and the other is a Gigabyte p35 ds4 (watercooled).