I gutted out the venerable fx6800e that served me so well and fit in a mATX by asrock, a 8400 and a new m.2 At first boot time was in the 7 seconds, and then I realized that the boot partition was not on the m.2 but instead it was an old SATA SSD. So I disconnect all the SSD and redo the OS install. Now bootup is 4 seconds. from ON to desktop. It's fast. I returned the 1700x because it never quite worked right and also because the cpu feels like needles in my head. The intel chip on the other hand feels smooth. And smooth it is, beside the boot time, and app startup, project build is on par with the Ryzen, compile is much faster, no stutter during games, overall it feels nimble.

About the fan configuration, I chose the u12s for the cpu because the numbers were close enough to the u14s and I realized once installed that I barely have space to the case panel, the 14s wouldn't have fitted. Kryonaut instead of the noctua gel, just because. I added a 12 and a 14 in push pull configuration and let the Asrock amazing BIOS do the magic, by setting up a response curve that shuts off the fan below 40C. It's an important detail because the u12s vibrates when the fan spins, I contacted Noctua support about that, I think the fan is faulty. The vibration is an unpleasant low frequency that carries far away. The 14 isn't mounted traditionally because I didn't want to bother with drilling holes so instead I glued some velcro to the corners. I use Velcro a lot, all the sata ssd are mounted this way, the nvme stays hot at 38C but the others stay at 20-ish, I may increase the 14 and 12 speed a little to keep the motherboard cool and, unlike the u12s, those fans don't spin until 40% power is applied.

HW-monitor doesn't recognize the motherboard unfortunately, so I do everything in the bios. The bios is very good, easy to navigate and behaves as expected... well except if you mess around with advanced boot options then you may have to restore the bios to factory.

Notice in the photo that all the fans are off, that's when under very light load. The PSU also doesnt spin. It is The Sound Of Silence

EDIT: the PSU fan started to spin. The PSU was getting heated up by the cpu radiator which rarely ever spins to push the heat backward. So I added some case flow by cranking up the front fan to 380 rpm and the rear fan to 430 rpm. 40% power is their minimum to spool up.