I am planning to wire a 4U DIY JBOD top loader.
Looking at the power output of several power supplies they have a a maximum rated 5v rail of 100-125w. By looking at the spec sheet of my chosen HDD I'll require more than double for all drives. There is plenty of current available on the 12v rail and I'm wondering if it's reasonable practice to use a 12v to 5v DC-DC converter?
Single drive active: 12v 0.56a = 6.72w | 5v 0.65a = 3.25w | total = 9.97w 64 drive active: 12v 35.84a = 430w | 5v 41.6a = 208w | total = 638w
The spin-up power is well over 1600w so I'll be using staggered spin-up.
With 8 dedicated SATA power cables from the PSU I can power 8 drives on each one. The cable has 18AWG wires which should handle 8 drives over a distance of less than 300mm. There I could put an inline DC-DC converter.