I bought two PROMISE PEGASUS R1-6 (Thunderbolt1, silver): one in 2011 and the second unit in 2013.
2011 R1-6: 6x Ultrastar 4TB disks, RAID-6
2013 R1-6: 6xSeagate NAS 4TB, RAID-6
Both units worked flawless, for many years...
I did measure IO speed, and it was 650MB/sec originally. In 2019 IO...