I have to say Batch 4, definitely an improvement from the other batches... not to mention brand sparkling new PSU suggest it was not pre-mined like the S1s.

I have 4 x Batch 4 S2 running - totalling 3.99 TH/s with 1.3% reject rate... Each miner is pulling 1040W from the wall. Board temperature between 41C - 51C.

So far so good...