My case fans are always running can I control them through motherboard?

Toggle sidebar Toggle sidebar
R

rohram04

Reputable
Nov 5, 2017
68
1
4,635
I just built my pc in the nzxt s340 elite and it came with two fans that have 3 pin fan connectors. Currently they are attatched to a molex which goes straight to the power supply. Could I plug these 3 pin fan connectors into the 4 pin fan headers on my asrock b250m pro 4 motherboard? Would this allow me to control the fans and when the spin. It is fairly loud even when I am doing some light browsing and I don't like it. While gaming I am fine with the fans on as the system would get really hot but while browsing....
 
Solution
P
I'm pretty sure the answer is no. In your mobo's manual the labels on the two CHA_FAN headers indicate they use only PWM Mode for controlling their fans, and that mode can NOT control the speed of a 3-pin fan. If you want to be absolutely sure first, see your manual on p. 65 where it describes the settings options available for each fan header. For those CHA_FAN headers, look closely to see whether there is any option to set the MODE to either PWM Mode or Voltage Control Mode (aka DC Mode). I expect there is no such option, but if you find it, try setting them to the DC Mode and connecting your fans that way, to see if it does work.

Assuming that does not work, you have two ways to get those fans under mobo control. The most obvious is...
Sort by date Sort by votes
cluedude2210

cluedude2210

Prominent
Nov 2, 2017
87
0
710
Nope, as long as the fans are connected to Molex you can’t control them through PWM, I would recommend buying a splitter so you can connect them to your motherboard for control.
 
Upvote 0 Downvote
R

rohram04

Reputable
Nov 5, 2017
68
1
4,635
No it is a splitter. I can take the fan headers out and plug them into the motherboard but they are 3 pin not 4 pin. My motherboard only has 4 pin chassis fan connectors.
 
Upvote 0 Downvote
P

Paperdoc

Polypheme
Ambassador
Oct 19, 2006
11,275
1,031
69,340
I'm pretty sure the answer is no. In your mobo's manual the labels on the two CHA_FAN headers indicate they use only PWM Mode for controlling their fans, and that mode can NOT control the speed of a 3-pin fan. If you want to be absolutely sure first, see your manual on p. 65 where it describes the settings options available for each fan header. For those CHA_FAN headers, look closely to see whether there is any option to set the MODE to either PWM Mode or Voltage Control Mode (aka DC Mode). I expect there is no such option, but if you find it, try setting them to the DC Mode and connecting your fans that way, to see if it does work.

Assuming that does not work, you have two ways to get those fans under mobo control. The most obvious is to replace them with 4-pin fans. The other is to buy and install the Phanteks PWM Hub. It is a Hub that accepts the PWM signal from a mobo header and gets power from the PSU. But unlike other such Hubs, this one actually uses its own circuits to convert to Voltage Control Mode. It has six output 3-pin ports, and you can plug your 3-pin fans into them and it WILL control them by the mobo CHA_FAN. IF you do that, there's one other item to check and maybe change on manual p. 65. For the CHA_FAN header you plug the Hub into, set the "Chassis Fan Temp Source" to use the sensor built into the motherboard, and not the one inside the CPU chip. Remember to SAVE and EXIT after making this change.
 
Upvote 1 Downvote
Solution
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom