GPU fan speed slight dip under full load vs load removed quickly

[realflow100]

if my GPU is under full load with the fans already at 100% then I remove the load on the GPU the fans will suddenly increase in RPM slightly for a few moments until the temperature drops low enough for the fans controller to reduce the fan speed (I have the fans set to an extra aggressive fan curve so they will go to 100% under full load)

I am annoyed by that dip and i'm wondering if I could rig up some kind of external power supply for the fans and use a voltage divider with a transistor hooked up to the GPU's fan output to control the power from the power supply going to the fans separately. so I dont get such a dip when the GPU is under full load and a spike in fan speed when the GPU usage drops.

so the GPU fan speed will reach 100% just a bit before it reaches 100% in software and can stay at 100% even if that little dip happens. so about 2% tolerance would probably be enough to stop that dip from happening

I dont have any issues with performance or stability its just annoying.

I'm not use if that transistor voltage divider thing would work though. or how to set it up. i would need a wiring diagram.

 

[iko22]

If the fans are already at 100%, then I do not see how they can increase RPM.

 

[realflow100]

Thats not the problem

When the GPU load drops from 100% before the temperature has a chance to drop the fans will speed up a little as if there was some kind of voltage drop occurring under load and it's bothering me!

 

[iko22]

...

I dont have any issues with performance or stability its just annoying.

I'm not use if that transistor voltage divider thing would work though. or how to set it up. i would need a wiring diagram.

Hard to implement something in hardware. To begin with you would need to know if the fan controller is analogue or PWM. Most modern controllers are PWM, which means you cannot build a custom circuit whose output is proportional to the input.

Therefore, Best look for a Software solution. You can do custom fan profiles with MSI Afterburner. Whether that would work on your Zotac card, I do not know.

Are you using a SFF case? A bigger case with more case fans should dissipate any audio distractions that you might have.

 

[LMiller7]

I would not recommend hardware modifications. There are many way this could go wrong and result in serious damage. Modern electronics does not lend itself to amateur modifications. I serviced electronics for 30 years and would not attempt what you are proposing.

 

[realflow100]

Its a small case and I dont have any other case available that I could use or any that I could buy that would fit the hardware i currently have
its a SFF case and the motherboard is OEM so its IO ports are not in a standard position. so no other aftermarket case would work.

the only other option is to change my fan profile so its quiet then I cant notice any fan speed spikes or dips but then it wont cool as well anymore. i like my GPU staying cold so it lasts longer

 

[NoN]

Looking at the specs: ZOTAC GAMING GeForce GTX 1650 Low Profile | ZOTAC your graphic card need at least 75W which is the limit of the Pci-e Slot, recommended power supply is 300W..

It takes it's power from the PCIe slot and provide power up to 75W, looks also at your System Specs you show on this forum you're very tight with your actual power supply.

The Graphic card seems to caliber or resetting the fans as it looks retain.

 

[realflow100]

what?
I upgraded the power supply now to a 430W one and its fine
but still most of the time I never see the GPU use over 90% TDP in GPU-Z its stuck at 69 watts and never even gets close to 75W and says its reaching power limit in GPU-Z
no matter what game or program i use to test.

 

[NoN]

Yes i saw you just upgraded from stock 230W to a new 430W. Your hardware components might have a good breath now.

I do not own Nvidia card but surely there must be a setting controling the fans in it?

 

[realflow100]

I can control the fan speed thats not the problem though its just when they are close to 100% and the GPU usage drops from 100% to like 50% or something for a short period of time i hear the fans speed up a tiny bit due to some sort of voltage drop when its under full load. and so when theres a short period of low load but fans still at 100% the voltage is slightly higher making the fans go a tiny bit faster
and it bothers me hearing that fan speed bump sometimes. its unnatural

 

[NoN]

Looks unnatural but necessary for the health of your graphics. Maybe this card use this kind of system to caliber itself after a stress load.

 

[realflow100]

same thing happened when I had a GTX 1050 ti LP though. really weird