Thanks for the advise, I went for: - one SSD in the Thunderbay (managed by Disk Utility) as a startupdisk (APFS/non raid) - my home directory on t...

Currently I have this setup: - iMac 21, 2015, 1TB fusion drive (28GBSSD/5400 HDD) - Thunderbay mini, 4*250 GB SSD, thunderbolt 2, with softraid lit...