We want to see the voltage deviate as little as possible from 12V. The be quiet! Dark Power Pro 11 850W is an 80 PLUS Platinum-rated supply that should do best in our tests, though only a Chroma electrical harness is able to differentiate between the minute variations in delivered performance from our trio of supplies.
The cross-load focus, in the first instance, loads the supplies with 70A on the 12V line(s) and 2A on the 3.3V and 5V. Cross-load 2 turns the tables and places 12V on the two minor lines and just 2A on the meaty 12V. The purpose here is to see how well the supplies respond when lines are pushed and pulled in opposite directions.
Predictably, there's very little between them, which is good news for Corsair as the RMx 850W retails for significantly less than the other two PSUs.