Question System fans display 0rpm even though they're spinning

Jul 2, 2021
11
1
15
0
So I recently bought this fan hub of amazon: https://www.amazon.co.uk/gp/product/B087LT27PZ/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1



I bought this because there was no space on my motherboard to connect my back fan. So I connected all my system fans to the fan hub, and then connected the fan hub to a sysfan header on the motherboard. After all that I checked my hardware monitor, for me I use dragon centre, and it says my system fans are spinning at 0rpm, even though they are clearly spinning very fast, I tried connecting the Radiator fan to the hub and then plugging the hub into the CPUFAN header, but I got the same problem, I don't know why it's doing that, was I meant to plug the hub into the pump fan header and and plug the pump fan into cpu fan headers.

tldr: got new hub, hardware monitors don't display sys fan speed, need a fix.
 
for the hub to transfer proper statistical data from the fan(s) to the motherboard they all need to be the same model fan.
when using different fans the hub cannot differentiate between the different RPMs so just shows a default 0%.

if you are using identical fans on the header and it's not reading properly,
probably just need a better fan hub.
 

Zerk2012

Titan
Ambassador
So I recently bought this fan hub of amazon: https://www.amazon.co.uk/gp/product/B087LT27PZ/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1



I bought this because there was no space on my motherboard to connect my back fan. So I connected all my system fans to the fan hub, and then connected the fan hub to a sysfan header on the motherboard. After all that I checked my hardware monitor, for me I use dragon centre, and it says my system fans are spinning at 0rpm, even though they are clearly spinning very fast, I tried connecting the Radiator fan to the hub and then plugging the hub into the CPUFAN header, but I got the same problem, I don't know why it's doing that, was I meant to plug the hub into the pump fan header and and plug the pump fan into cpu fan headers.

tldr: got new hub, hardware monitors don't display sys fan speed, need a fix.
Well it's nice you linked the fan hub BUT you never listed the fans if your using regular 3 pin powered fans then their nothing to report from them since you need the 4th pin to report any RPM information.
 

Zerk2012

Titan
Ambassador
for the hub to transfer proper statistical data from the fan(s) to the motherboard they all need to be the same model fan.
when using different fans the hub cannot differentiate between the different RPMs so just shows a default 0%.

if you are using identical fans on the header and it's not reading properly,
probably just need a better fan hub.
Not really true and he never listed the fans.
EDIT most of the time a fan hub that supports 4 pin fans will just have one plug and depend on that one for the rpm READING
 
most of the time a fan hub that supports 4 pin fans will just have one plug and depend on that one for the rpm READING
while there may be some that operate that way,
every nice 4pin > 4pin hub i've ever setup needs to have identical RPM ranges for them to be properly controlled and properly reported to the motherboard's header.

while showing a % in regards to RPM may function that way,
actually reporting correct RPMs of different fans would be impossible.
and what would be the point of having an accurate RPM value of one out of multiple different fans connected to the same hub?
 

Karadjgne

Titan
Ambassador
Pwm fans don't read specific rpm afaik, they read the duty cycle and convert that to rpm. So fan speed ranges from different fans are irrelevant, they'll all be at the same duty cycle, but only one fan is actually read (usually the #1 slot). This matters to performance as a 1000rpm fan at 50% is going to be spinning slower than a 1500rpm fan in #2 slot at the same 50%, or reversed if the 1500 is in #1.

3pin fans do read rpm, but actual speeds are not controlled by the rpm but by the voltage, so whichever fan is in #1 slot will be the control fan for all fans in the hub.

A hub is nothing more than a solid powered splitter, only 1 lead will have all wiring connections, the rest will not have the sensor pin connected. All controlled by the voltage/duty cycle of the #1 fan. Rpm of all other fans is non-existant.
 
Last edited:
Jul 2, 2021
11
1
15
0
Well it's nice you linked the fan hub BUT you never listed the fans if your using regular 3 pin powered fans then their nothing to report from them since you need the 4th pin to report any RPM information.
The fans on my pc came with the case and they are 4 pin 12V DC 0.2A
 

ASK THE COMMUNITY

TRENDING THREADS