Odd PSU issue - loud GPU fan

OZONE · 24 Sep 2020 at 09:45

I purchased a Prime TX-750 and noticed the GPU fan randomly ramps up to 100% during gameplay. It becomes extremely loud under certain occasions. I swapped it for an Asus Thor 850W, and the GPU remains whsiper quiet during gameplay. Tested it with the same game and same scene (Borderlands Pre-Sequel).

Could the TX-750 be faulty? It's not coil whine. I measure the RPM using MSI Afterburner and it always ramps up to 1800rpm+ time from time with the Prime, but doesn't appear to go past 1200 rpm with the Asus.

pastymuncher · 24 Sep 2020 at 15:00

Is this a Corsair TX750-M? If so do you have it in the bottom of the case with the fan facing up? If you do that will probably be the cause. The Asus ROG Thor 850w has a zero rpm fan until the psu hit's a certain load or temp meaning that the fan is usually off until it has a decent power draw. The Corsair TX750-M doesn't have this and has the fan on all of the time meaning that the gpu is fighting it for airflow, hence the higher fan speeds. The easiest way to sort it would be to put the psu the right way around with the fan facing down providing your case has a vent for it in the bottom and there is enough clearance under the case for the psu fan to suck in air. This is all based on a hunch that you have it set up as above.

OZONE · 24 Sep 2020 at 17:33

This is the graphics card fan which spins to infinity. The PSU remains quiet either way.

pastymuncher · 24 Sep 2020 at 20:16

You haven't clarified anything. Is this a Corsair TX750-M and is it mounted in the bottom of the case with the fan facing up? If you have the psu fan facing up then the gpu fans will be fighting with the psu for airflow and will have to work harder to cool your gpu. In this situation the Asus psu wouldn't cause the gpu fan to work harder as it has a zero rpm mode which the Corsair doesn't have. If the Corsair psu fan is facing the gpu they will both be fighting for airflow hence the gpu fans spinning faster.

OZONE · 24 Sep 2020 at 23:09

pastymuncher said:
You haven't clarified anything. Is this a Corsair TX750-M and is it mounted in the bottom of the case with the fan facing up? If you have the psu fan facing up then the gpu fans will be fighting with the psu for airflow and will have to work harder to cool your gpu. In this situation the Asus psu wouldn't cause the gpu fan to work harder as it has a zero rpm mode which the Corsair doesn't have. If the Corsair psu fan is facing the gpu they will both be fighting for airflow hence the gpu fans spinning faster.

It's a Seasonic Prime TX-750.

In both instances I had the fans facing down, and I disabled the zero RPM mode.