Hello,
I picked up my RTX 3080 FTW3 yesterday and have been tinkering around on settings, installing new games and reading up.  While the card is relatively still new, am hoping to find some advice or recommendation on fan control. 
I am using the Precision X1 software.  When FAN SPEED is set to AUTO, it appears to run a 0RPM curve, and perhaps runs adaptively once the card is hotter?  My question is, is this the recommended fan curve?  Or should I click FAN SPEED and check Fan Curve Control and use a preset or create a custom?  Should I have the fans spinning at all times, or let it adaptively cool the card?  I always feel slight worried when the fans aren't spinning, but if the card is designed for this type of mode and is recommended, would use that.  
 
I appreciate any information!

What do you use for your fan curve?  Can you screenshot?

By default, on the Normal BIOS, the card will run in a 0 RPM mode & only start the fans up once you hit a certain temperature (something like 55C if I recall correctly).
 
I use the following fan "curve", it's more a of a step ladder, keeps the card cool when I'm gaming, and turns the fans off when I'm not:
 

 
Note that this is REALLY aggressive, 50% as soon as the card comes out of "sleep"/2D mode is pretty high, but I also can't hear it through my headphones and the case at all to be honest.  Even at 80%, it's not that audible with the given noise floor in my room (I almost always have a room fan and AC or heater running which results in the noise-floor in the room being high enough that I literally can't hear my computer at all despite it having... 16 fans in it not including the PSU or the GPU's fans? lol) 

Followed your recommendations and this is my fan curve.