Running 3 case fans off of mobo fan header?

[Frying CPUs]

Just built my 1st rig. Waiting on a 3 way fan splitter to hook all my case fans together. Would it be ok to hook the splitter to the fan header on the mobo? I cant find any info on how much power each fan draws or the output of the mobo fan header. 

 

Mobo is a gigabyte b350 ds3h x370 

case fans are fans in a diypc bg-01 case. Exhaust fan has a blue led as well if it matters. Thanks.

[Streetguru]

12 minutes ago, Frying CPUs said:

 

Probably not the best idea, should just get a sata or molex fan adapter or just use more than 1 port on the board.

[corrado33]

28 minutes ago, Frying CPUs said:

Just built my 1st rig. Waiting on a 3 way fan splitter to hook all my case fans together. Would it be ok to hook the splitter to the fan header on the mobo? I cant find any info on how much power each fan draws or the output of the mobo fan header. 

 

Mobo is a gigabyte b350 ds3h x370 

case fans are fans in a diypc bg-01 case. Exhaust fan has a blue led as well if it matters. Thanks.

The fan usage will be on the back of the fan. Usually the headers on the motherboard are either 12W or 5W. A normal (non LED) fan uses about 2 W. My fan sitting on my desk uses 0.16A at 12V, which is 1.92W. Therefore I could put, at most, 6 fans on a 12W header. Read the voltage and amperage on the back of your back fan, then calculate it based on that. 

 

I'm pretty sure that MOST modern motherboards' 4 pin fan connections are 1 amp meaning 12 W. 

[Frying CPUs]

24 minutes ago, corrado33 said:

The fan usage will be on the back of the fan. Usually the headers on the motherboard are either 12W or 5W. A normal (non LED) fan uses about 2 W. My fan sitting on my desk uses 0.16A at 12V, which is 1.92W. Therefore I could put, at most, 6 fans on a 12W header. Read the voltage and amperage on the back of your back fan, then calculate it based on that. 

 

I'm pretty sure that MOST modern motherboards' 4 pin fan connections are 1 amp meaning 12 W. 

Just checked my fans. Front 2 (no led) has 12V === 0.25A. Rear Fan (led) has 12V === 0.25A on it as well. Im horrible with electrical numbers so I'm not sure what each draws out. Thanks for any help. Looked up a calculator and punched in the numbers, does 3 AMPs per fan sound about right to you? So I could run 4 fans off one header if said statement about modern boards putting out 12W on fan headers? 

[corrado33]

Assuming the fan header is a 1A one, you could run 4 fans off of one header (barely.) The CPU fan header is almost guaranteed to be a 1A (12W) one. 

 

Considering your board only contains 2 fan headers, you can be pretty sure that they're both 1A (12W) ones. So you could run 4 fans off of each, although I'd probably stick with 3. 

[Frying CPUs]

1 fan header is taken up by my mastercooler evo 212 and the system fan header is used up by the rear fan. 

[corrado33]

2 minutes ago, Frying CPUs said:

1 fan header is taken up by my mastercooler evo 212 and the system fan header is used up by the rear fan. 

If I were you, I'd hook both the CPU fan and rear fan to the CPU fan header, then all 3 front fans to the system fan header. 

[corrado33]

Also make sure that the CPU fan is hooked to the splitter FISRT, because only the first fan is monitored for speed.

 

EDIT: Or just look into the splitter's headers and hook the CPU one up to the one that has 4 pins not 3. 

[Frying CPUs]

1 minute ago, corrado33 said:

If I were you, I'd hook both the CPU fan and rear fan to the CPU fan header, then all 3 front fans to the system fan header. 

hmm. I really dont want to fight with this thing again lol. Could I run my 3 case fans (2 front, 1 rear) off system fan header and just leave my evo 212 hooked to cpu fan? And my system run fine? Reason Im asking this is because my brother has the same case and fans and hooked all his to the system fan header and used a splitter to run them. 

[corrado33]

Just now, Frying CPUs said:

hmm. I really dont want to fight with this thing again lol. Could I run my 3 case fans (2 front, 1 rear) off system fan header and just leave my evo 212 hooked to cpu fan? And my system run fine? Reason Im asking this is because my brother has the same case and fans and hooked all his to the system fan header and used a splitter to run them. 

Yep, you could do that just fine. I thought you had 3 fans up front. 

[_Hustler_One_]

It's fine as long as 3 fans draws no more than 1A current total.

I use my Noctua NH-D15 with 3 fans on it and all of the 3 fans are connected to a single CPU_FAN header. The 3rd cooler fan also acts as the rear exhaust fan. Runs without problems.

[Daniel644]

8 hours ago, Frying CPUs said:

Just checked my fans. Front 2 (no led) has 12V === 0.25A. Rear Fan (led) has 12V === 0.25A on it as well. Im horrible with electrical numbers so I'm not sure what each draws out. Thanks for any help. Looked up a calculator and punched in the numbers, does 3 AMPs per fan sound about right to you? So I could run 4 fans off one header if said statement about modern boards putting out 12W on fan headers? 

Watts is Volts times Amps, the fan headers operate on a 12 volt rail, so a 1 amp header allows for 12 watts of total power, your fans are 0.25 Amps each, you total all 3, thats 0.75 AMPS or 75% of capacity of the 1 AMP header, provided your fan header is indeed a 1 amp header (most modern ones are now from my research) then you are perfectly fine running those 3 off a splitter, I personally have 3 Corsair maglevs running off a header, if you have any real concern over having enough power a SATA 12 volt rail (one run of sata power cable) can handle 4.5 amps, you can get a fan hub that is powered off a SATA connection like this thing https://www.amazon.com/Electop-Chassis-Cooling-Port-Controller/dp/B07416KLWJ/ref=asc_df_B07416KLWJ/?tag=hyprod-20&linkCode=df0&hvadid=309809835998&hvpos=1o2&hvnetw=g&hvrand=7672408562019576105&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9011033&hvtargid=pla-570806499301&psc=1 to run all your fans and maintain a PWM (provided your fans even support PWM control).