Dynamic fan speed cable setup

Splisendyson

Solid State Member
Messages
10
Okay, I have a motherboard, 1 CPU fan, and 4 case fans.

Power supply: several 4 pin molex connections
4 x Case fan connectors: 1 x 3 pin female
CPU fan connectors: 1 x 3pin female, 1 x 4 pin female
Motherboard: 1 x 3 pin male, 1 x 4 pin male (both directly next to the cpu)

I want to buy the correct cable, or cables and possibly different fans. My ultimate goal is to allow the case to monitor the temperature inside of the case and adjust the fans accordingly.

Possible ways:
1) Buy a 1 x 4 pin female to 5 x 4 pin male, let's call it the Special Fan Power Cable. The setup: Mobo 4 pin ->SFPC->(CPU & Case Fans). Mobo 3 pin -> CPU.
Would this use the CPU's temperature gauge to adjust ALL of the fans?

2) Buy a 1 x 3 pin female to 5 x 3 pin male (SFPC2)
. The setup: Mobo 4 pin -> CPU. Mobo 3 pin -> SFPC2 -> (CPU & Case Fans).
Would this use the CPU's temperature gauge to adjust ALL of the fans?

3) Buy 4 new case fans with 4 pin connectors. The setup: Mobo 4 pin -> SFPC -> (CPU & new Case Fans). Mobo 3 pin -> CPU.
Would this use all fans' temperature gauges to adjust ALL of the fans?

----

The main question is exactly what is going on with that 4th pin? All I know is that it is involved in power regulation.

Why does the CPU need a 3 pin AND a 4 pin? If the 4 pin is made to power and regulate the CPU fan, then the 3 pin must be a backup? Or can one remain unplugged?

Is the Motherboard taking temperature data and adjusting fan speed based on the 4 pin and only adjusting the speed on the 4 pin port? Or is it adjusting fan speed on both the 4 pin and the 3 pin ports?

Ia it possible for all 5 fans, including the cpu fan, to send the motherboard temperature data when they are being split like with SFPC I described? If not, do I need more Mobo 3 or 4 pin connections to make my Mobo capable of multiple temperature readings and fan speed adjustments?

By now I think you see where I'm going with this. :)

Also, I'm new and my name is Delta. I have been out of the computer world for a couple years due to ups playing kickball with my computer and being poor in general, but I can finally afford to rebuild her and I want to hear all of those fans switch between stealthy and silent when idling at night to a nice purr when I kick on BF4 (=

Thank you in advance for any insight you may provide and for the use of this forum. (You might want to check on the phone app cus my new Galaxy S5 doesn't have a button to make a post, hehe. )
 
Thankyou very much. :) Like I said, it's been a while haha

also, why does the CPU have both 4 pin and 3 pin fan connections? Should I be plugging in both?
 
Last edited:
Thankyou very much. :) Like I said, it's been a while haha

also, why does the CPU have both 4 pin and 3 pin fan connections? Should I be plugging in both?

just because its next to the CPU doesn't mean its only for the CPU.
could be for cases with top mounted fans. or for the pump in a AIO water cooler like the corsair h50. 1 connection for the fan, 1 for the pump.
 
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