I wanted to build a custom portable rig aiming to be as small as possible (6L) so I thought I'd do some modding to my Zotac GTX 1080 Ti Mini to prep for my build.
1) BIOS - EVGA GTX 1080 TI SC ( https://www.techpowerup.com/vgabios/191595/evga-gtx1080ti-11264-170406 - thanks @teisysadmin)
This allow for 0RPM mode, fans start kicking in around 50C. But more importantly, it allows for custom fan curve to go all the way down to 0%. With the stock bios, the fan curve was locked at 44% minimum. This makes for a noisy run even at idle. Now with this bios, it's much more quiet especially for non-gaming activities.
2) Liquid Metal - Removed original TIM and replaced with Liquid Metal
3) Using 1 large BeQuiet 135mm fan instead of 2 smaller fans. This works very well and the fan is very quiet.
4) Stable Undervolt (3dmark stress to make sure for long term stability)
@ 1810 Mhz - 900mV
@ 1911 Mhz - 1000mV
10% more power consumption and louder for 5% performance gain, not worth it to me...
A) Stock OC - 40 Idle (because of 0RPM mode), 75C full load
B) Undervolt @ .9V @ 1810 Mhz - 40C Idle, 65C underload ( ~40% fan speed)
C) Undervolt @ 1V @ 1911 Mhz - 40C Idle, 75C underload ( ~55% fan speed)
Very happy with the results from these mods as the card now run very quiet and with a .9V undervolt lock, the coil whine is also much more tolerable as it doesn't fluctuate as much. Undervolt will be my 24/7 settings. Doesn't look great (and frankly ghetto), but you can't argue with the results!