Can someone confirm, that the fan is much louder after upgrading the 2017 5k 27” i5/3.4GHz to a i7/4.2GHz (with i7 7700K)?...

So, it seems to be normal, I also checked the temperature and speed with Intel Power Log 3.7, it seems that 4.2GHz is only available for a few seconds, the processor is throttled down to approximately 4.0 GHz when running all cores at 100%. Temperature is about 96°C, Fan Speed about 2700 rpm, what is the maximum speed. So I think when upgrading a iMac 5K 2017, the 4.0 GHz i7 will be enough because the cooling system is not good enough to handle the i7 7700K at 4.2 GHz for more than a few seconds.

I also did it with the same adapter, ordered for a few bucks from china.

I’m usign the 970 EVO Plus 1TB, they have updated the firmware and it works out of the box.

The firmware for older models can be updated directly on the mac with the updater from Samsung (can be installed on a USB stick and used to start the mac with it)

The standard 970 EVO does not have had the firmware issues, just the Plus had in the past.

For the blade SSD no OWC cable is required, that is only if a SATA-HDD is replaced by a SATA-SSD, thats a completely different thing.

For point 10 of this guide: iMac 27” 2017 has a relocated microphone position, so if you follow this guide, the mic ist not working after applying the tape.

Make sure to let the microphone out, its located on the lower edge, right of the apple.

Also the tape Stips on the upper edge are 2mm too long, and on the upper right it does not fit to the antenna area, so they have to be shortened and cut in the right shape.