Doubts about 3-pin headers in 4-pin motherboard headers

MOS_6502

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May 2, 2014
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Hello to all.


Some days ago, after changing some cables, I disconected two molex to 3-pin adapters (these were connected to the PSU), and as they were not very good, the metal pins of the two molex connectors were broken.

Just right now I don't have money to buy two adapters, so I thought on connect the fans that doesn't have adapters in the 3/4 pin headers of the motherboard, but I have some doubts:

My motherboard is a Gigabyte GA-F2A88X-D3H, the two fans are an Artict Cooling F12 and a Scythe Katana (I don't remember wich one), and the latter aren't PWM

This is the diagram for the fan headers:

ZxA1Wk.jpg


and this, is the configuration of the said motherboard headers under the BIOS:

T7JEIA.jpg



and my doubts are those:


1 - I've read that I can use 3-pin headers in the ones of 4-pin, that's correct?
2 - The only thing required to plug a 3-pin header in a 4-pin one is to align the notch found in the 3-pin header with the one of the motherboard and the fan will work without any issues?

3 - Check the 2nd image that i've attached to this thread, under "1st/2nd System Fan Speed Control" setting, if I set it to ">>Disabled Allows the fan to run at full speeds" I can plug on those the two non-PWM fans?

4 - The last one doesn't appear after the 1st/2nd (SYS_FAN3, check the first image) and if I see the PIN description, I think that it doesn't have any sort of PWM or voltage control (correct me if I'm wrong, that's what I understand after seeing the connector diagram), because I don't see anything more related to it in the manual; if I plug one fan to it directly (a non-PWM one), the said will work correctly and it wil spin at full speed?


Many thanks for your time.
 
Solution
1 yes that is correct
2 yes, there is a notch, the plug will only go in one way.
3 You can still control the fan speeds with the three pin fans, so i would not set it to disabled, unless you like a loud pc.


PS if those are your only two fans in your pc. just connect both to the two 4 pin connectors on the motherboard and set the speed in your bios. Connecting fans to the motherboard is always a better solution than using the molex adapters.

huvik

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Apr 27, 2015
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1 yes that is correct
2 yes, there is a notch, the plug will only go in one way.
3 You can still control the fan speeds with the three pin fans, so i would not set it to disabled, unless you like a loud pc.


PS if those are your only two fans in your pc. just connect both to the two 4 pin connectors on the motherboard and set the speed in your bios. Connecting fans to the motherboard is always a better solution than using the molex adapters.
 
Solution

MOS_6502

Honorable
May 2, 2014
68
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10,640


Hello, thanks for the response.

I sucesfully tested the two fans in the SYS_FAN01 and SYS_FAN02 ports (4-pin), there are no problems, works great. By other hand, there's more fans on my system, but those two were essential for a correct heat dissipation; some days ago the ambient temp were low, but yesterday the temp rose very quickly and I'm using an APU (+ the integrated graphics) and I don't want to fry it.

Many thanks! I will pick your response as the solution.