Multiple fans connected to one 3 pin header?

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DarkDubzs

Limp Gawd
Joined
Jan 3, 2014
Messages
354
Is it safe and possible to connect 4 or 5 case fans to a single 3 pin fan header on a mobo? I want to add four of these case fans to my rig, theyre 3 pin, and i dont want to spend more money on a fan controller, so i want to just connect them to my mobo and i can control their speeds via software. So, would it be okay to do that? My sad, cheap mobo, btw: http://www.newegg.com/Product/Product.aspx?Item=N82E16813130662

Also, my mobo only has one 4 pin cpu fan header, one 4 pin system fan header, and one 3 pin system fan header. Could i connect two 3 pin fans to the 3 pin header, and two more to the 4 pin header... to keep the headers safe and last longer (and keep my mobo from frying)? Im just worried about connect 3 pin fans to 4 pin headers... is that okay and safe too? Would i also still be able to manually control the speeds of the fans connected to the 4 pin headers via software on my pc?

Lastly, if i connect multiple fans to a single header, like via a header hub(http://www.newegg.com/Product/Product.aspx?Item=N82E16811997110) or splitter(http://www.newegg.com/Product/Product.aspx?Item=N82E16812189063), will software be able to see the individual fans and control them individually or will i just see one fan because i am connecting multiple fans to a single header?

Please help. Thanks in advance!
 
most mobos have 1amp max fan headers, those fans have a 0.2amp rating. Be aware that start up amps will be higher
 
First off the only difference between a 4 pin header and a 3 pin is that last pin is used for Pulse Width Modulation for precise fan speed control. In your case that pin would be left open and the other 3 pins are the same (power, ground and RPM). I have never tried using a Y adapter to power more than one fan from the motherboard, I imagine if you connected two fans like this your RPM reading would be added together. There is a Hall Effect sensor inside the fan that activates twice per revolution, which is divided in half to give you the RPM reading. It is up to your motherboard manufacturer to provide speed control from the BIOS or from software, some cheap motherboards skimp on this. I have an Intel motherboard with a CPU and System fan, I was not able to adjust the speeds directly from speedfan, but I set a minimum speed in the BIOS and they throttle up when the temps rise. The other fans in the case are powered from the Power Supply using a molex adapter. This seems to work well for me in my case. The Hub you linked to includes a molex plug to connect directly to the power supply, I wouldn't connect it to the motherboard. If you want absolute control over your fans the best option would be a dedicated fan controller. Although you could try connecting 2 fans to each header and not using one of the RPM wires (they should be the same anyway, and yes they will be controlled as if they were one fan). You could start by doing some experimenting with your system, connect one fan to each header and see what options your BIOS offers and see if you can control them from the software. Let me know how it goes for you!
 
That adapter in your case would just power the fans at 12 volts, Unless you purchase 4 pin PWM fans. Also notice on the close up pics, only one fan has one header with a RPM reading.
 
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