There are many factors that affect the auto ranking capacity.
For starters, Neural is generally assumed to be on.
A memory implant can usually lower requirements to 20x atk 10x energy or something comparable
And then there is the aviliablity of Drannik sabs. If you can afford to sab everything, you can make do with 15x atk 10x energy or so if you put up implants, while if you don't have any, it might require up to 30x atk 10.5x energy to 25x atk 11x energy w/o implants.

And in case someone is being random and doing it as a human.... it can require even less~

So there really isn't one single answer~ dah rich can auto rank ez while the poor... oh brother...