Powering multiple pi's and multiple external hdds

Question

I have looked around here and on other sites but don't really come to a clear solution on what to do specifically with my setup.

I'm searching for a way to power the following setup efficiently:

Basically:

• 1 Raspberry PI 1
• 1 Raspberry PI 3

• 3 Raspberry PI 3 B+

• 2 SEAGATE Expansion Portable (2015) 1TB

• 1 TOSHIBA Stor.E Canvio Basics black 1TB 2.5"
• 1 WD unknown 512GB
• 1 unknown 1TB

I didn't know that I need to power those HDD's externally when I bought them and now I'm therefore struggling to provide enough power for them.

I tried to connect a Y cable to a second port of the PI, which worked better for one of the drives, but it still failed when I wrote a lot of data on it.

So now I have the following ideas:

1. Buy 6 active power hubs USB 3.0 Power Hub, 4 USB Ports + 2.4A Charging Port, 15W(5V/3A) power adapter. Since this hub has a special port for charging, I thought it would be optimal for my problem. Attach them the following way:

2. Two Anker PowerPort (60W 6-Port USB Charging Hub) and a couple of USB Y cables. Connect them like this:

Is there a better way compared to those two, I want to reduce power adapter usage, don't want to use 12 since that seems a bit overkill? And if there is no better solution, which one should I use?

Answer 1

You are creating a wiring medusa of power. :D Let's chop that complexity down a bit.

Since you are building your own datacenter, consider datacenter solutions. For example multiple computers are rack or blade mounted in a datacenter. Similar solutions exist for the Raspberry Pi. We do not endorse individual vendors, but you can easily find such solutions yourself.

You should also consider RAID drives

Answer 2

You have asked a couple of shopping questions, but most of these are inappropriate.

If you want to power 5 Pi in a frame DON'T use 5 PSU. It is cheaper, and more reliable to use a single PSU. In fact, this is what most Pi clusters use.

I use one of the 5V switch mode PSU designed to run LED light strips - these are well regulated. Choose one with a suitable current rating - 12A would seem appropriate for the layout you specified.

You COULD use 5 USB cables, but most such applications power through the 5V pins on the Expansion header - this makes it easy to use decent sized cables. See Raspberry Pi Power Limitations for further information.

The self powered HDD are probably not the best choice, but as you have them you could try powering from the Pi. Whether this works reliably depends partly on the HDD - some of mine work, others don't - I normally use a powered hub, but 5 hubs would be clumsy.

You could either use Y-cables or make a custom cable to 5V power and isolate from the Pi 5V. All the drives can be powered from the same PSU.

Answer 3

RPi 3 should be able to power a hard disk attached to it, provided it receives enough power itself. HDD plugged into RPi 1 should probably be powered by a Y-cable or be self-powered.

In total, each RPi would consume about 1A, and so would each HDD. If I were you, I'd buy a single 5V / 10A power supply and use it to power all the RPis and the HDD you plan to plug in the RPi 1. Instead of USB hubs, you could simply buy DIY USB connectors and make your own power cables for the RPis. Alternatively, you could power the RPis via the pin header.

HDDs could be attached to RPi 3 by regular USB cables, provided you pick cables which are thick and short, so that they can carry the necessary current.