3 fans 1 header

Awood1342

Awood1342

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Currently running 2 bitfenix spectre 120mm and 1 140mm off of one header..
Is this going to cause an issue?

the fans current
120mm fans -0.16a +- 10% putting a max of 0.176 by my calculations so a combined of 0.352a
140mm fan- 0.19a +- 10& putting a max of 0.218

so total current of 0.6 max lets say for arguments sake.

done some research and a lot of people say the max current from a header is 1 amp

im doing this using a bitfenix 3pin x3 3pin extension

is this going to cause any damage what so ever?

should i switch to a molex and run them straight from the psu?

Thanks
 

Awood1342

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have considered it but finances say cant afford it till next pay day, this is just a temporary thing in my new machine and i don't want to damage it
 

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It'll be fine. 1A is a lot of fans. I've had to use more than 10 of my collection of fans to simulate a 1A fan load.

The fan ratings are typically lower than those specified on the blurb or the fans. If they are standard 120mm Spectres then they are actually more like 0.08A at full tilt. I forget what the 140mm Spectre was but it wasn't significantly more.

You could probably run 6 or 7 standard Spectres on a single 1A header.
 

Awood1342

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That's good news!

One thing I did note when I first plugged them in they didn't spin without a little nudge. Is this to do with the wattage rather than current. Though they were brand new and I just attributed it to them being stiff.

Fan controllers on my hit list aswell or atleast the little black nzxt box thing that overclocker sell.

So in general I can't damage my mobo with this configuration?

Thanks for reply also :)
 

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It won't be anything to do with the Watts the fans are using. Motherboard fan headers are constant voltage output devices so will basically present 12v, or thereabouts, to the fan load no matter how many you attach. If they are properly regulated you shouldn't see a voltage sag at all.

What may be happening here is that the motherboard header is set to voltage control, whereby the BIOS/MB software is presenting a lower regulated voltage to the fans while the CPU temperature is low.
 

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Awood1342 said:
Ahh so under load then the fans would kick in?
Click to expand...

If my thought is correct.

You really want these fans to be moving at all times though. In BIOS you may find a setting that describes the fan curve. Something like %/deg C. It may have a reference point for zero duty cycle as well.
 

Awood1342

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Something like 0.75w/degree I think is what I saw, not sure about a reference
Point though

Also speed fan doesn't like 3 fans on one header is their anything I can do about that
 

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If you want them to run at a constant speed, just get some Molex to 3-pin adapters. You can usually get them with 12v or 7v to get the fans to run at differing speeds. Dirt cheap and provides consistent, if uncontrollable power to your fans!
 

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Try adjusting the settings upwards and see what effect it has. As you adjust 0.75 to 1.0 and beyond you should see the attached fans speed up faster at lower temperatures than before. 0.75 may be too low at idle temperatures to get the fans to overcome the friction of the motor.

Or turn off fan control on that header and have the fans run at 100% all the time.
 

Awood1342

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So got home changed the settings in the bios menu and even on the maximum pwm/degrees available. 2.5w the fans still needed to be given a nudge to start, my guess is that my idle temperature is to low on boot to make a difference to how many watts are required. When i disabled control the fans did start by themselves but the noise was like a hoover haha.
 

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TheyCallMeAndy said:
Thats awful don't recommend that..
Click to expand...

Not awful in my opinion. It has a few issues but is generally reliable and automatically controls your fans.

The only issue I've seen is one where fans can speed up and down by 100-200RPM as they settle at a speed. This tends to happen for a few minutes only. This is sometimes an annoyance but if your PC is off to the side on the floor or something you may not even notice that. I have read that some people have greater issues than this though. I'm not sure if this was a early version release issue as my controller was given to me for review back when it was new out.
 

Awood1342

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Yeah my pc is off to the side on the floor, Bitfenix colossus is too big for a desk haha

also need somthing on a budget really as spent far to much of my wages on it this month already haha

and as im using bitfenix case and fans i thought it would add to the rig as a bitfenix controller, but im generally a noob so all thoughts and opinions are welcome
 
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