A 35" drive will typically use 12v for the motor and 5v for the circuit board A 25" drive will typically use only 5v, for both motor and circuit board The hard drive label will tell you the maximum power consumption and from which voltages that power is taken This tells you the hard drive will consume a MAXIMUM of 5w x 06a 12v x 045a 76 #2 the fastest hdd in 25 inch form is the western digital scorpio black it is far slower then the fastest 35 inch hdd > the Scorpio black will top out at 110 during a long big file copy lots of 35 inch hdds got to 140 what interests me about you link is the 70 rpm claim for a 25 inch hdd I use a lot of hdds I am notAnswer (1 of 2) Not at all You might even say that 25″ drives are built to be more rugged than 35 inchers, because they're usually deployed to laptops, and laptops are prone to being moved while in use (this was a nono in the early days of the hard disk!), or even falling from a table Anyw Seagate Constellation 2 And Conste