Fans questions

[PurplDrank]

Hello all. 

 

I have a b450 tomahawk motherboard and a fractal design meshify c case. I am looking to add more fans to my build but what is the difference between pwn and non pwn fans? Will my tomhawk support pwn or non pwn?

[Metallus97]

pwn? Its PWM

But generally there are PWM controlled and voltage controlled fans. Your mobo can do both but I recommend PWM. That gives better and finer control even across different models of fans.

PWM: 4 connectors (V+,V-,PWM, speed signal)

Non PWM: 3 (V+,V-,speed signal)

Mobo does detect only 3 connected -> regulates per voltage

Mobo detects 4: gives 12V all the time and lets the fan do the speed regulation according to PWM signal 0-100% given by the mobo)

[mariushm]

A fan can have 2, 3 or 4 wires ... and therefore it could have a connector with 2, 3 or 4 pins.

 

Wire 1:  +12v (+) , the power needed to spin the fan

Wire 2: Ground (-) , return path for the electricity going to fan

Wire 3: Fan Sensor (rpm) : Optional, the fan sends a signal to the motherboard and the motherboard can measure how fast the fan spins this way. If the wire is not connected, the motherboard simply isn't able to measure how fast the fan spins.

Wire 4: PWM : Optional, the motherboard can send a signal to the fan, and a chip inside the fan can adjust the speed of the fan according to the signal properties. By default, the fan spins at 100%, and the signal can set the fan between 10% and 100%. If the wire is missing, fan goes at 100%

 

So, only 2 wires are absolutely required, which means you can insert 3pin or 4pin connectors into a 2 pin fan header, or you can insert a 4 pin connector into a 3 pin header, leaving the optional wires in the air, unconnected to anything.

 

For the motherboard, it's easier to just tell the fan "set the rotations per minute to 50%" of maximum rotations possible and a tiny chip inside the fan adjusts the speed. The voltage remains 12v all the time, and the motor of the fan can be optimized for that.

Some motherboards have a smart chip on them which tries to send this command to the fan and when the fan doesn't change its rotation speed it's smart enough to realize that 4th wire may not be present, so it falls back to trying to change speed by adjusting the voltage sent to the fan. A lower voltage will make the motor of the fan spin at lower speed.

Just the same, some fans that support PWM are flexible enough to adjust their speed if inserted into a 2 pin or 3 pin fan header by letting that smart chip on the motherboard control the voltage going to the motor.

 

Changing the 12v to some lower voltage is a more difficult operation, and it's less efficient, so that smart chip on the motherboard may produce a tiny amount of heat in the process.

It's worth noting that some some fans that support PWM are much more optimized for this control, through a signal, so they won't support such a wide range of rotation speed through voltage control.

As an example, a PWM fan may adjust from 10% to 100% rpm speed through the 4th wire, but using voltage control, the fan may stop spinning when the voltage goes below 9v , where the fan may still spin at 60-70% of its maximum spin speed.

A fan which doesn't have PWM option may be adjustable from 12v (100% speed) all the way down to 4-5v, where you could have as low as 5-10% rpm speed.

 

So you can see a PWM fan as a superset of a classic fan with 2-3 wires, a smarter fan, which can work in any 2/3/4 pin fan header, but there's a fineprint (depending on fan, may not go to very low speeds if inserted in 2 or 3 pin headers)

 

 

[PurplDrank]

37 minutes ago, Metallus97 said:

pwn? Its PWM

But generally there are PWM controlled and voltage controlled fans. Your mobo can do both but I recommend PWM. That gives better and finer control even across different models of fans.

PWM: 4 connectors (V+,V-,PWM, speed signal)

Non PWM: 3 (V+,V-,speed signal)

Mobo does detect only 3 connected -> regulates per voltage

Mobo detects 4: gives 12V all the time and lets the fan do the speed regulation according to PWM signal 0-100% given by the mobo)

 

1 minute ago, mariushm said:

A fan can have 2, 3 or 4 wires ... and therefore it could have a connector with 2, 3 or 4 pins.

 

Wire 1:  +12v (+) , the power needed to spin the fan

Wire 2: Ground (-) , return path for the electricity going to fan

Wire 3: Fan Sensor (rpm) : Optional, the fan sends a signal to the motherboard and the motherboard can measure how fast the fan spins this way. If the wire is not connected, the motherboard simply isn't able to measure how fast the fan spins.

Wire 4: PWM : Optional, the motherboard can send a signal to the fan, and a chip inside the fan can adjust the speed of the fan according to the signal properties. By default, the fan spins at 100%, and the signal can set the fan between 10% and 100%. If the wire is missing, fan goes at 100%

 

So, only 2 wires are absolutely required, which means you can insert 3pin or 4pin connectors into a 2 pin fan header, or you can insert a 4 pin connector into a 3 pin header, leaving the optional wires in the air, unconnected to anything.

 

For the motherboard, it's easier to just tell the fan "set the rotations per minute to 50%" of maximum rotations possible and a tiny chip inside the fan adjusts the speed. The voltage remains 12v all the time, and the motor of the fan can be optimized for that.

Some motherboards have a smart chip on them which tries to send this command to the fan and when the fan doesn't change its rotation speed it's smart enough to realize that 4th wire may not be present, so it falls back to trying to change speed by adjusting the voltage sent to the fan. A lower voltage will make the motor of the fan spin at lower speed.

Just the same, some fans that support PWM are flexible enough to adjust their speed if inserted into a 2 pin or 3 pin fan header by letting that smart chip on the motherboard control the voltage going to the motor.

 

Changing the 12v to some lower voltage is a more difficult operation, and it's less efficient, so that smart chip on the motherboard may produce a tiny amount of heat in the process.

It's worth noting that some some fans that support PWM are much more optimized for this control, through a signal, so they won't support such a wide range of rotation speed through voltage control.

As an example, a PWM fan may adjust from 10% to 100% rpm speed through the 4th wire, but using voltage control, the fan may stop spinning when the voltage goes below 9v , where the fan may still spin at 60-70% of its maximum spin speed.

A fan which doesn't have PWM option may be adjustable from 12v (100% speed) all the way down to 4-5v, where you could have as low as 5-10% rpm speed.

 

So you can see a PWM fan as a superset of a classic fan with 2-3 wires, a smarter fan, which can work in any 2/3/4 pin fan header, but there's a fineprint (depending on fan, may not go to very low speeds if inserted in 2 or 3 pin headers)

 

 

Will these fans work with my motherboard?

 

https://www.bestbuy.com/site/thermaltake-pure-plus-12-led-rgb-triple-pack-radiator-fan-tt-premium-edition-120mm-case-cooling-fan-kit-with-rgb-lighting-black/6339072.p?skuId=6339072&ref=212&loc=1&extStoreId=402&ref=212&loc=1&gclsrc=aw.ds&ds_rl=1260666&ds_rl=1266837&ds_rl=1268709&gclid=CjwKCAiAx_DwBRAfEiwA3vwZYs5DnzDVZV14D1DBckCo3SVZhW9QCUAE5m2xOEz78A68290m-jWjXBoClqAQAvD_BwE

[mariushm]

Any fan will work with your motherboard. Read again what I explained and try to comprehend.

 

Some fan headers on your motherboard may not have the 4th pin so they won't send pwm signal to fan, in which case by default fans will run at 100%.  Those fan headers may or may not allow you to adjust the speed by adjusting the voltage on the header, as the pwm pin is not possible.

 

Those fans are a bit special.  They're designed to be plugged into a USB 2 header on your motherboard, or in the controller supplied in the package (which is basically a fancy usb hub that creates several usb 2 headers). They don't have the classic fan connector that goes into fan headers on your motherboard.

 

They're supposed to be used with a fan controller from Thermaltake which can then be controlled through software. The kit has the controller.

So each fan has a cable which you can plug either in a USB 2 header on your motherboard, or in the controller that's in the package.

If you use the controller, you need to connect the controller to the motherboard in a USB 2 header, and also connect it to power supply using a molex (old mechanical hard disk connector)

 

See manual : https://thermaltake.azureedge.net/pub/media/productattach/db/support/usermanual/_1d3e81e8847543f59b26d3a1e635c356.pdf

 

 

 

[PurplDrank]

3 hours ago, mariushm said:

Any fan will work with your motherboard. Read again what I explained and try to comprehend.

 

Some fan headers on your motherboard may not have the 4th pin so they won't send pwm signal to fan, in which case by default fans will run at 100%.  Those fan headers may or may not allow you to adjust the speed by adjusting the voltage on the header, as the pwm pin is not possible.

 

Those fans are a bit special.  They're designed to be plugged into a USB 2 header on your motherboard, or in the controller supplied in the package (which is basically a fancy usb hub that creates several usb 2 headers). They don't have the classic fan connector that goes into fan headers on your motherboard.

 

They're supposed to be used with a fan controller from Thermaltake which can then be controlled through software. The kit has the controller.

So each fan has a cable which you can plug either in a USB 2 header on your motherboard, or in the controller that's in the package.

If you use the controller, you need to connect the controller to the motherboard in a USB 2 header, and also connect it to power supply using a molex (old mechanical hard disk connector)

 

See manual : https://thermaltake.azureedge.net/pub/media/productattach/db/support/usermanual/_1d3e81e8847543f59b26d3a1e635c356.pdf

 

 

 

i do see on my mother board 2 pairs of 4-pin connectors that say jUSB1 and JUSB2....those may be the connectors i need. 

[mariushm]

They're not 4 pin, usb 2.0 headers have 9 pins ... it's a 2x5 pin header with one pin missing.

 

You connect the controller to one of those headers (and give power to the controller through a 2nd cable connected to molex on power supply), and then you connect the three fans to the controller

OR

you can probably connect one fan to one of those headers on the motherboard but you probably won't be able to control the RGB if the fan isn't connected to controller.

 

[PurplDrank]

56 minutes ago, mariushm said:

They're not 4 pin, usb 2.0 headers have 9 pins ... it's a 2x5 pin header with one pin missing.

 

You connect the controller to one of those headers (and give power to the controller through a 2nd cable connected to molex on power supply), and then you connect the three fans to the controller

OR

you can probably connect one fan to one of those headers on the motherboard but you probably won't be able to control the RGB if the fan isn't connected to controller.

 

That wouldnt matter to me. The standard on those is rainbow color. Thats what my cpu fan is anyways