8-900 watts from wall, 2 rigs per 15/20amp circuit?

Here’s the deal, I need more power… until I get more power, I was running 1 rig per circuit, now I put 2 rigs per circuit and it doesn’t trip the breaker unless I plug something in that uses roughly 1-200 watts aprox. So assuming I don’t use this circuit for anything else, even lights, besides these 2 mining rigs in the one room. Should be fine? Power wires are not warm or hot or anything like that. Each rig uses roughly 8-900 watts from wall constant. I have 2 plugged into 1 circuit to test this for now.

I’m no electrician so I’m not sure if by 15/20amp you mean some standard notation which I’m not aware of or you just mean 15-20A, because you’re not sure what the rating of the circuit is.
I think you’ve left out an important part though; what the voltage on your circuit is and what is the exact rating of the circuit breakers.

Basically if it runs on 220V then: 900W / 220V =~ 4A
But if it runs on 110V then: 900W / 110V =~ 8.18A (which is about double)

Since you say that by plugging an additional appliance it trips the breaker, I assume it might be the later.

The first right question, I guess, is: Are you sure the circuit uses the correctly rated circuit breaker (i.e. they were installed by an electrician and/or if they were replaced it was done with an equally-rated breaker)?
If the answer is yes, then at least you’re not in danger of setting your house on fire.

Provided that the breaker is of the correct rating for your circuit, then I guess that on an 20A even at 110V you would be safe with only the 2 rigs as it subscribes the circuit at about 80% of its capacity.
If you’re on a 15A circuit at 110V then I’d say you’re constantly reaching its limit and even oversubscribing it whenever both rigs draw more than 825W at once and the wiring in the wall could get really hot.
It might be fine but stressed at the limit nonetheless.

Just my 2 cents, so take it with a grain of salt.