Case fans 3 and 1 header on mobo

[qamararfin]

So I have 3 led case fans with 3 pin and molex both and my mobo has 1 header for fan and I do have three way splitter so connecting it is no problem but I'm not sure if I should as it is led fan and 3 would suck power from one header which might not be healthy for mobo. For now I have connected rear one to mobo and 2 front with molex but they running full speed making me annoyed.
Also I wanted to ask if i should connect 3 pin and molex both so that it can take power from molex and instructions from 3 pin?
Any suggestion would be helpful.

 

[hotaru251]

molex will make fan run @ 100% speed.

 

[Aeacus]

While it's true that when connecting 3x fans on single MoBo fan header you could overload your MoBo fan header, frying it and on worst case scenario also brick your MoBo, there's also a better solution for your issue in form of a fan hub.

Since you have 3-pin fans in use, Thermaltake Commander FX would suit your needs the best,
specs: https://www.thermaltake.com/Cooling/Cooling_Accessory_/Fan_Controller/C_00002391/Commander_FX_10_Port_Fan_Hub/design.htm
amazon: https://www.amazon.com/Thermaltake-Commander-SATA-Powered-AC-007-AN1NAN-A1/dp/B00O5VX6UQ
It can control only 3-pin fans via DC mode and it doesn't support 4-pin fans. Supports up to 10x fans.

Or Phanteks fan hub, specs: http://www.phanteks.com/PH-PWHUB.html
amazon: https://www.amazon.com/Phanteks-PWM-Fan-Controller-PH-PWHUB_01/dp/B00M0R05WE
It is unique since it can control both, 3-pin and 4-pin fans via PWM mode. Supports up to 6x fans.

Note: regardless the fan hub used, all the fans connected to it will run in sync. If you want individual control over your fans, you'll need a fan controller.

 

[qamararfin]

Thanks
It was helpful.

 

[qamararfin]

Also
Can I connect all three fans with splitter to mobo and all three fans to psu molex. Then it might get power from psu and speed will sync with each other.

 

[Aeacus]

Since your fans have 3-pin connector and molex as well, plugging in the molex would override the 3-pin connector and make the fans still run 100% at all times. So, just use the fan hub and control their speed within BIOS. Btw, with 3-pin connector, fan still gets all it's needed power from it since the fan hub itself is also powered by sata/molex cable.

 

[qamararfin]

Since your fans have 3-pin connector and molex as well, plugging in the molex would override the 3-pin connector and make the fans still run 100% at all times. So, just use the fan hub and control their speed within BIOS. Btw, with 3-pin connector, fan still gets all it's needed power from it since the fan hub itself is also powered by sata/molex cable.

Thanks.
My curiosity has been satisfied.