I use my Raspberry mainly as a fileserver. I've attached 3 harddrives, 1 of them being an SDD and 2 Mechanical 3.5 Drives. When powered on, everything seems to work. However, when booting, the initial boot of both the mechanical drives draws too much energy, so the Pi crashes and is stuck in a loop.

This makes rebooting dangerous since I cannot trust the PI to be reliable with those HDDs attached. What can I do?

  • 2
    As per the answer you are unlikely to power multiple spinning disks directly from a any model of Pi.
    – goldilocks
    Feb 5, 2021 at 18:39
  • Not a duplicate exactly but very similar raspberrypi.stackexchange.com/questions/19516/… where you could use a powered USB hub and 3x cables as pictured.
    – Criggie
    Feb 6, 2021 at 12:14

1 Answer 1


I'm assuming these are USB drives, and are powered from the Pi USB port(s).

You're probably exceeding the power supply capacity of the Pi and/or the power supply. Hard drives require a fair amount of current to operate- even more on startup.

The only way you're going to get this to work is to use a powered USB hub. Make sure the hub has its own power supply and can supply enough current to make all three drives happy (check the drive specs and add up the required currents). Plug the hub into the wall. Plug the hub into the PI, plug the drives into the hub.

  • That's interesting... So all three drives are independently powered? Have you tried attaching fewer drives to see if the Pi boots with one or two? Is one of them your boot drive?
    – BobT
    Feb 5, 2021 at 23:32
  • No, regular internal SATA drives, connected to an adapter like this. It's not only USB powered, it also draws 'regular' power. Thats why I'm surprised this issue even exists. (sorry, reposted because I was trying to format)
    – Piplup
    Feb 5, 2021 at 23:34
  • Except the SSD, the 2.5 SSD is directly powered via USB. With just 1 HDD removed, everything works again. However, under load (copying data) the Pi sometimes crashes too. Doesn't happen with the SSD. It's gotta be the power load, and it's really annoying, but I dont understand the problem, since the mechanical drives are independently powered.
    – Piplup
    Feb 5, 2021 at 23:39
  • @Piplup Possibly the chip still uses the 5V from the USB to power itself, to convert the SATA to USB and USB to SATA. And the external power supply only powers the HDD. I'm not sure if this is what is really happening, but it is my guess. Feb 6, 2021 at 4:45
  • You'd think that the SSD's would draw less current but that's not always the case. BTW, are you seeing a little 'lightning bolt' in the upper right portion of your screen? That's the way the Pi tells you it's overloaded. I'd still recommend using a powered hub for your external drives... It's a layer of power isolation.
    – BobT
    Feb 6, 2021 at 19:17

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