Does a motherboard know the temperature of its PSU?

dssdghthd

Honorable
Jan 14, 2013
63
0
10,640
The sound of the PSU fan was driving me crazy, so I replaced it with the front header fan. The front header fan is still connected to the motherboard, so I set it to act like a PSU fan in BIOS. But the thing is, how would the motherboard control this fan properly if it doesn't know the temperature of the PSU? And why is there even a "PSU fan" option in BIOS if motherboards don't know the temperature of the PSU?
 
Some PSU do provide info back to the motherboard, but it should be connected to the power header and not the case fan headers, to ensure that the fan is spun at the correct rpm or you'll end up cooking the psu. PSU connection cable normally only has the yellow rpm monitoring wire connected to header plug.
 

dssdghthd

Honorable
Jan 14, 2013
63
0
10,640


I can't connect the fan directly to the PSU, the connector has an extra wire and won't fit.
Would a 120mm fan running constantly at 670 rpm be sufficient to cool a PSU?