Where to plug in Corsair H105 Fans? + Y-Splitter Question

[Based Panda]

For my new build, I have replaced the stock H105 fans with a pair of Corsair SP120 Quiet Editions. I am using the NZXT H440 case, and I have a few questions regarding where and how I should plug these fans in.

1.The two ends of the Y-splitter are oriented like this: ||_| and |||| Why does one of them have a gap, and how would I plug the two fans (3-pin) into the splitter?

2.Where should I plug in the splitter - the 10 fan hub that is built into the NZXT H440 or a motherboard fan header? Also, will I be able to keep track of the fans that are plugged into the hub? I do not see that they are connected to the MOBO in any way.

Thanks in advance!

 

[hwc1954]

The "gap" on the splitter connector is a missing 3rd pin. This is the pin that returns tach speed information from the fan to the motherboard so the system can know how fast the fan is spinning. You can only have one fan reporting tach speed to each header. If you had two fans on a splitter sending tach information, it would be a mess. So, all good splitters have the 3rd pin removed on all but one fan connector.

If the two fans you are connecting are identical, it doesn't matter which one you connect to each side of the Y as they will be turning at the same speed. If they are different, then pick which one you want to know the speed for and connect that to the side of the header with all the pins.

 

[Based Panda]

The "gap" on the splitter connector is a missing 3rd pin. This is the pin that returns tach speed information from the fan to the motherboard so the system can know how fast the fan is spinning. You can only have one fan reporting tach speed to each header. If you had two fans on a splitter sending tach information, it would be a mess. So, all good splitters have the 3rd pin removed on all but one fan connector.

If the two fans you are connecting are identical, it doesn't matter which one you connect to each side of the Y as they will be turning at the same speed. If they are different, then pick which one you want to know the speed for and connect that to the side of the header with all the pins.

So even if the fans are 3-pin, I can still use this splitter to power both of them? Also, should I plug the two fans into the MOBO or the fan hub that comes with the case?

 

[hwc1954]

A 3-pin fan can be plugged into a 4-pin splitter. The first three pins are the same. And the design of the notches on the plugs ensures that the plug can only be inserted properly. A -3-pin fan plugged into a 4-pin splitter will have a GROUND connection, a +12V power connection, and a TACH speed connection (if that pin has not been removed from the splitter). It will not have the fourth pin (a PWM control signal connection).

A 4-pin splitter can be connected to either a 4-pin or a 3-pin jack on the motherboard. If a 3-pin fan is connected to a 4-pin fan header (through a splitter or not), it will usually get constant +12V power and run at full speed.

I can't answer your question about where to hook up the fans because it depends on the motherboard. If your motherboard offers the option of variable +12V speed control, then you could hook the fans up directly to the headers. If not, it might very well be that the "fan hub" is providing this capability. That would take some research in your motherboard's user guide. Often, there are user settings in the BIOS configuration.