I'm not running them off a main unit. I am running them individually connected to a PC. Right now they're making about 800 satoshis a day each, which I can't imagine is worth the time I'm taking to post this this. So I'm obviously a bit disappointed. Maybe when I switch to another pool they will be able to mine a little better, of course by separating them from the rest of my miners there will be increased fees for withdrawals and a slower time to reach a payout amount worth an additional input when it's eventually spent. Maybe I'm doing something wrong or just plain dumb, but I don't think these miners would be profitable for most, if any of the users buying them when you consider residential electricity costs and the idea of cooling in the summer. It was close with the given specs. Real life usage, not so much. As a space heater they're ok.
800 sats would mean less than $10 a month at current rates. Which PSU are you using? The advertised 3.8TH/s cannot be achieved with the bundled 200W PSU and requires more watts.
Our FutureBit 200W power supply is limited to ~ 3 TH/s, 3.8 TH/s is only achievable with an external > 300 watt power supply.