Just a reminder, a rule-of-thumb is if you're running a 'continuous' load (i.e. mining rig 24/7), you should never exceed 80% of the rated circuit's capacity. So a 20A circuit at 80% capacity is 16A or 1920VA(W)'s. It's part of the NEC code.
Like most rules, it's 'meant to be broken', but I thought I'd just throw that out there.
Cheers,
Kermee