How many LED fans does my motherboard support?

acecreator26

Commendable
Mar 9, 2018
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I have a Gigabyte AB350 Gaming 3 motherboard which supports Gigabyte RGB Fusion. I have a GTX 1080 TI which has LED support and is linked to my motherboard lighting. So when I use my RGB Fusion app on my PC it changes the colors on the graphics card and on the motherboard.

I am looking to replace my current 120mm fans with LED 120mm fans. I know for a fact that my motherboard supports these fans because I clearly can see a 4 pin connector on my motherboard and the fan has a 12V 4 pin connector. I am sort of a PC noob so I am not sure if some of what I'm saying is true for all fans and motherboards, but I'm just saying it because it's somewhat relevant. On the motherboard there are 2 LED 4-pin connector spots that I see but I have 3 fans I want to replace. Does this mean that I can't add all 3 LED fans because I don't have 3 LED spots? I also can't tell if the second LED spot is taken by the graphics card because the graphics card itself is blocking my line of sight.

Like I said I'm kinda a noob at this and I just don't want to waste my money if what I'm trying to do isn't even going to work in the end. If someone experienced could help that'd be great. Thanks in advance.

https://www.flickr.com/photos/144228308@N07/45678578835/in/dateposted-public/
 
Solution
You can use a PWM fan splitter to connect multiple fans to a single fan header on the motherboard. However, you do have to be careful to not draw too much power from a single fan header. Too much power draw can damage the motherboard. Refer to your fan's specifications to find out the power draw for each fan. Refer to your motherboard's manual to find out the maximum power draw from each fan header. Typically the maximum power draw from each fan header is 1 A.

I could not find this information in your motherboard's manual and specifications. I recommend defaulting to 1 A as the maximum power draw.


For example:

The fan header on your motherboard provides a max power draw of 1 A

The fan (Corsair ML140 PRO) has a power draw of 0.276 A...
You can use a PWM fan splitter to connect multiple fans to a single fan header on the motherboard. However, you do have to be careful to not draw too much power from a single fan header. Too much power draw can damage the motherboard. Refer to your fan's specifications to find out the power draw for each fan. Refer to your motherboard's manual to find out the maximum power draw from each fan header. Typically the maximum power draw from each fan header is 1 A.

I could not find this information in your motherboard's manual and specifications. I recommend defaulting to 1 A as the maximum power draw.


For example:

The fan header on your motherboard provides a max power draw of 1 A

The fan (Corsair ML140 PRO) has a power draw of 0.276 A

3 of these fans will have a power draw of 0.828 A

Because the fans draws less power than the fan headers limit, you can connect three fans to that header with a Silverstone Technology 1-3 PWM Fan Splitter Cable.


Amazon: Silverstone Technology 1-3 PWM Fan Splitter Cable
https://www.amazon.com/dp/B00HJOJS9O/

Corsair ML140 PRO specifications:
https://www.corsair.com/us/en/LED-Color/Fan-Size/Package-Quantity/ml-pro-led-config/p/CO-9050047-WW
 
Solution

acecreator26

Commendable
Mar 9, 2018
90
6
1,665


I am looking at a MasterFan Pro 120 Air Flow RGB and on the specs page it lists out 2 numbers for power.

Rated Current (A): 0.17
Safety Current: 0.40A

I copied these specs straight from MasterFans website so they are 100% correct. Now, being the noob that I am, which one of these numbers am I supposed to be adding up? I was assuming the Rated Current is what I should look at, if it was, it would be perfectly okay to hook up 3 of these fans to the same header. But, if it is the .40 I wouldn't be able to. Like I said if you could clarify this that would be amazing, and thank you for your response because it cleared up a ton of confusion.
 
I am glad you brought this up. The safety current is the fan's maximum load. The rated current is the fan's safe operating load. There is a risk of damaging the fan if it is at load higher than the rated current during normal operation. However, there is one time where the fans will be operating higher than the rated current. That time is when the fans startup. We do not know how much load the fans are drawing at startup unless we actually measure it. What we do know is that the startup load is not higher than the safety current.

What does this all mean in relation to how to connect the fans? The safety current is what you should be adding up. If you plan on using the MasterFan Pro 120 Air Flow RGB with a safety current of 0.40 A, then the safest setup is two fans per header. If you connect three fans, there is a possibility of a power draw of 1.20 A from the fan header during startup. This may result in damage to the fan header.

If the fan does not specify a safety current like my example above, I recommend leaving 15%-20% headroom. My example leaves approximately 17% headroom.