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Is it ok to run 2 pwm fans from a single fan header using splitter?

EzioWar
By EzioWar
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Go to solution Solved by RONOTHAN##,
5 minutes ago, EzioWar said:

Hi, is it ok to run 2 pwm fans (mayb 2x fans on cpu cooler in push pull) from a single fan header using splitter?

Depends on the fan, but it's probably fine. 

 

6 minutes ago, EzioWar said:

is it harmfull in any way?

It can be if it overloads the header. Fan headers are rated for a certain amount of current (usually 1A, but there are some that are higher), and fans at full speed draw a certain amount of current (this will be printed on the fan hub and listed on the spec sheet). If you get a pair of fans that additively draw over an amp, it can burn out the fan header. However, unless you buy server fans, it's rare for a fan to draw over 1/3 an amp, so running even three fans on a header is usually safe. 

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Hi, is it ok to run 2 pwm fans (mayb 2x fans on cpu cooler in push pull) from a single fan header using splitter? is it harmfull in any way?

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That's the whole point of splitter cables. Hell, a dual-fan cooler usually comes with one in the package so you can run it from just the CPU_FAN header.

You can usually safely go up to three fans on a single header.

4 is technically possible but it depends on actual fan power draw so avoid it if possible, or use a SATA/MOLEX-powered fan hub at this point.

 

Though you should always check the actual mobo and fans spec sheets.

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9 minutes ago, EzioWar said:

Hi, is it ok to run 2 pwm fans (mayb 2x fans on cpu cooler in push pull) from a single fan header using splitter? is it harmfull in any way?

Unless you're running high-velocity server delta fans, you shouldn't pull nearly enough current for it to be a problem. Some coolers even include an adapter like that since most boards only have one CPU fan header. 

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  • Solution
5 minutes ago, EzioWar said:

Hi, is it ok to run 2 pwm fans (mayb 2x fans on cpu cooler in push pull) from a single fan header using splitter?

Depends on the fan, but it's probably fine. 

 

6 minutes ago, EzioWar said:

is it harmfull in any way?

It can be if it overloads the header. Fan headers are rated for a certain amount of current (usually 1A, but there are some that are higher), and fans at full speed draw a certain amount of current (this will be printed on the fan hub and listed on the spec sheet). If you get a pair of fans that additively draw over an amp, it can burn out the fan header. However, unless you buy server fans, it's rare for a fan to draw over 1/3 an amp, so running even three fans on a header is usually safe. 

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1 hour ago, EzioWar said:

Hi, is it ok to run 2 pwm fans (mayb 2x fans on cpu cooler in push pull) from a single fan header using splitter? is it harmfull in any way?

You can check in manual or support website for your motherboard. Example: https://www.gigabyte.com/Motherboard/B550-AORUS-ELITE-V2-rev-10-11/sp#sp

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16 hours ago, EzioWar said:

Hi, is it ok to run 2 pwm fans (mayb 2x fans on cpu cooler in push pull) from a single fan header using splitter? is it harmfull in any way?

A lot of PC fans draw less than half an amp each, maximum. Ronothan's answer was excellent. Without knowing the fans you're referring to, we cannot directly answer you.

 

The Arctic P12 Max, for example, draws .29A, whereas the Noctua NF-A14 iPPC-3000 draws .55A. So, while you could run 3 of the Arctic on a 1A header, you could only run one of the Noctua on a 1A header. In both cases, if you had an additional fan that would not put the total draw over 1A, you could add more.

I've been using computers since around 1978, started learning programming in 1980 on Apple IIs, started learning about hardware in 1990, ran a BBS from 1990-95, built my first Windows PC around 2000, taught myself malware removal starting in 2005 (also learned on Bleeping Computer), learned web dev starting in 2017, and I think I can fill a thimble with all that knowledge. 😉 I'm not an expert, which is why I keep investigating the answers that others give to try and improve my knowledge, so feel free to double-check the advice I give.

My phone's auto-correct is named Otto Rong.🤪😂

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If you are going to run a fan in series off a mobo header, you should be ok. You want to avoid hot plugging your fans.. it unfortunately took me 3 mobos and a header from each one from hot plugging a certain fan that I use on occasion to learn that lesson. They were good boards too lol.. 🫠

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2 minutes ago, freeagent said:

If you are going to run a fan in series off a mobo header, you should be ok. You want to avoid hot plugging your fans.. it unfortunately took me 3 mobos and a header from each one from hot plugging a certain fan that I use on occasion to learn that lesson. They were good boards too lol.. 🫠

How is running fans in series going to be okay if the fan series exceeds the amperage limit of the header? Or did I miss something?

 

Which fan?

 

I've been hot-swapping fans from 120mm to 220mm for over a year and, aside from accidentally shorting an EZDIY-FAB fan that apparently has different wiring, I haven't managed to burn out my mobo headers. (I realize you've been doing it a lot longer than me, and probably way over the 200ish fans I've done it with.) Then again, I mostly stopped using the PWM headers for this purpose, but I still do it with my RGB and ARGB headers. Risky? Worst case scenario is that those headers burn out and then I won't even notice because I really don't use LEDs unless I'm testing, and I've got a PWM+ARGB hub for that. Any advice?

 

 

Sorry, OP, for going a bit off-topic on this.

I've been using computers since around 1978, started learning programming in 1980 on Apple IIs, started learning about hardware in 1990, ran a BBS from 1990-95, built my first Windows PC around 2000, taught myself malware removal starting in 2005 (also learned on Bleeping Computer), learned web dev starting in 2017, and I think I can fill a thimble with all that knowledge. 😉 I'm not an expert, which is why I keep investigating the answers that others give to try and improve my knowledge, so feel free to double-check the advice I give.

My phone's auto-correct is named Otto Rong.🤪😂

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36 minutes ago, RevGAM said:

Which fan?

DC Koala 3 😄

 

It’s a little 92x35 4000RPM knuckle blender. It’s awesome lol, probably the strongest fan that I own 😄

 

It will indeed make the pwm controller pop and flash, but consumer grade fans are pretty weak.. so not really a concern I would think.

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1 minute ago, freeagent said:

DC Koala 3 😄

 

It’s a little 92x35 4000RPM knuckle blender. It’s awesome lol, probably the strongest fan that I own 😄

 

It will indeed make the pwm controller pop and flash, but consumer grade fans are pretty weak.. so not really a concern I would think.

What's the draw, AF and SP?

I've been using computers since around 1978, started learning programming in 1980 on Apple IIs, started learning about hardware in 1990, ran a BBS from 1990-95, built my first Windows PC around 2000, taught myself malware removal starting in 2005 (also learned on Bleeping Computer), learned web dev starting in 2017, and I think I can fill a thimble with all that knowledge. 😉 I'm not an expert, which is why I keep investigating the answers that others give to try and improve my knowledge, so feel free to double-check the advice I give.

My phone's auto-correct is named Otto Rong.🤪😂

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2 minutes ago, RevGAM said:

What's the draw, AF and SP?

It’s a P3 era server fan, info has been tough to find. For shear airflow and pressure it will embarrass a 140mm iPPC 3K..

AMD R9 5900X | Thermalright Phantom Spirit 120 EVO, T30,TL-C12 Pro
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Seasonic Vertex GX-1000 | Fractal Torrent Compact RGB, Many CFM's

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19 hours ago, EzioWar said:

Hi, is it ok to run 2 pwm fans (mayb 2x fans on cpu cooler in push pull) from a single fan header using splitter? is it harmfull in any way?

Do you have any more questions?

I've been using computers since around 1978, started learning programming in 1980 on Apple IIs, started learning about hardware in 1990, ran a BBS from 1990-95, built my first Windows PC around 2000, taught myself malware removal starting in 2005 (also learned on Bleeping Computer), learned web dev starting in 2017, and I think I can fill a thimble with all that knowledge. 😉 I'm not an expert, which is why I keep investigating the answers that others give to try and improve my knowledge, so feel free to double-check the advice I give.

My phone's auto-correct is named Otto Rong.🤪😂

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