My s21pro 234 just finished its first month of air cooled hashing. No problems so far other than the fans ramping up and down continuously. I stuck an ac infinity to it to quiet it down.
I just dunked it today in my foghashing C6. A few not so minor things. The s21 is taller and longer than the s19. This means I can’t fit two s21 side by side in the C6. Best the C6 can do is 4 s21 perpendicular to the coolant supply holes on the bottom. Im doing 2 s19 and two s21 total so not a big deal for me but if you were planning on 6s21 in the C6, that’s not going to happen.
S21 is longer than the s19 which means it almost sticks up out of the coolant. This might effect the liquid’s ability to flow through the machine case. I can close off the slots in the overflow pan which I might have to do later. I’m going to closely monitor its heat levels for the next few days. We’ll see how it goes.