We need the name of the powersupply manufacturer, and if possible the model line.
and the total amount of volts it can supply at each amps (volts times amps equals watts). It should be written like this
At Temp Z
Yv X Amps, 5v XAmps, 12v XAmps etc
Now the most helpful information is how many combined watts (when all the rails are active) it can supply at 12v but often they don't say this on the label if they are a cheaper psu company. (note this number isn't all the 12v rails added together for while 1 rail may supply X amps, when you have 2 or more rails they can't supply their maximum individual load at the same time only a percentage.)