You have 62A on 12v, so if that's the case your 24 drives would peak at 48A of current when you turn on the PC. the 5v current will not be significantly higher. So, reserve 1A for each SSD.Įdit: Yeah, the motor on mechanical drives will consume more current when it starts up, up to 2A or so on 12v.

Reserving 0.75A of current on 5V for each mechanical drive, in theory you should be able to add up to 18 / 0.75 = 24 mechanical drives.Ī SSD consumes less power, around 1w when idle and reading files, but during long periods of writing some SSDs can consume up to 5-8 watts, and all this is from 5v - pretty much all SATA SSDs are 5v only.

So assuming the motherboard and other things in your computer (usb devices, chipset, onboard sound, optical drive, whatever) needs around 4A of current on 5v (20w), this means you have at most 18 A of current on 5v. Your first limitation will be the maximum output current the power supply can provide on 5v, which in your case is : It will take up to 0.5-0.8A from 5v (~4w) and up to around 0.5A on 12v (6w) A mechanical drive will consume around 8-10 watts, from 5v and 12v.

One drive psu