As the specification table above shows, the U-75HA features four +12v rails rated at 18a each with a maximum load of 648w (54a). This realistically brings the maximum output of each rail down to 13.5a if each rail were to be equally loaded at the same time (as we will be doing during the testing). Interestingly the ASUS website calls these rails "real four 12V rails" which by our definition is highly unlikely as it would require four separate 12v transformers. More realistically the U-75HA has one 12v transformer that is 'virtually' split into four with over current protection kicking in at 18a on each of the' virtual' rails.



Link: Overclock3D