I'm looking for a quiet 850W PSU and struggling to make a decision between

- The new Corsair AX850
- Seasonic Prime Ultra Titanium 850W
- EVGA 850 T2 (optional candidate)
(Not looking for ~600W fanless PSUs)

I've read the OC3D review of Corsair AX850 that the unit still runs passively after 20 minutes of full load, which is what I want. But the report from Cybenetics shows the fan starts at around 400W load.
On the other hand Seasonic's fan starts a bit earlier but at lower RPM overall.

Most of the time I use my PC browsing the web, watching Youtube. Sometimes gaming and video/audio editing/rendering.

Spec (everything air cooled):
i7 8700k 4.9GHz @ 1.3v
Asus Z390-E
4 x Kingston HyperX Fury 16GB 2666 1.2v
Nvidia 1080 FE (no OC yet)
Samsung 970 EVO 500GB, 860 EVO 1TB
2 x 5.4k SATA 2.5" HDD 2TB
5 x noctua A12x25
Fractal Design Define C

I'm currently using EVGA 850 G3 with ECO mode ON and it's the noisiest component. The PSU fan suddenly ramp up to quickly cool itself down after idling on desktop around 5-10 minutes and then back to passive mode and then ramp up again... repeat and repeat. Even with ECO mode off I still don't want that constant fan hum from the PSU. That's why I'm changing it.