Power Input review​

After reiterating our board design and going through the community feedback we decided to improve the “dummy” 5V USB-C power input. It supposedly might be all right for a prototype, but not an appropriate solution for the production version.

Why? Simply because we don’t want our users to suffer from the underpowered device which is quite likely with such a plain USB-C power input setup.

One solution could be to support a USB-C Power Delivery (PD) and/or Quick Charge (QC) with internal voltage negotiation. For example a range of  9V, 12V, and 20V (this was originally suggested by k3nal on Reddit). But such power adapters are pricey. A Ponkor 65W USB-C PD for instance, costs around 30 EUR, a 100W SPLAKS PD even a bit more than that. Would you be willing to pay that price?

An alternative option is a simple 12V input via a barrel socket with a max 5A current. This will be a solution for x4 2.5′ HDDs/SSDs. Additionally, a 12V input for external ATX PSU support.

In order to settle on a plan of action, we need your feedback. Please answer the two questions below. (We appreciate your help)

What is your preferred setup (up to four drives)?

What is your power input choice?

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44 thoughts on “Power input review”

    • How about we look at what it’d cost to offer it as an option. As for SSD vs. Spinning rust…

      You’re not going to gain much, overall, over the spinning rust and it IS more expensive, so you want/need to plan for the “worst” on power profile- which is still fine for considering USB-C PD. The problem with USB-C PD, while it’s sexy and modern, it’s…heh…EXPENSIVE to be honest with you.

  1. Since a NAS ist usually not a mobile device, there ist no need for a mobile-style power supply.
    This makes USB anything dispensable.
    Just a decent smps, or even a linear power supply, will do.
    I could imagine to use a readily available (Meanwell or other) module to keep cost down and reliability up.
    The possibility to use a linear PS would cater nicely to “audiophile” pseudoscientists.

  2. What is about an external PSU for a notebook? These have 19 Volts and some have enough power for 4x 3,5” drives. You can add a power converter. But to find a PSU device with 12 Volts with more than 5 Ampere may be difficult.
    How do big manufacturers the job to support 4 or more 3,5” drives in a small case and without a ATX PSU?

  3. First iteration for production, keep it simple. USB-C adds complexity and cost for what gain? Others have noted that you can get very cheap little adapters that will convert PD -> 12v for not much money, even then they can be hit and miss as PD/QC+ varies across power supplies. You don’t want to be dealing with those sort of headaches on a first production.

    *Maybe* you’ll want to accept a voltage range above 12v (say 14 -> 24v, common in cheap plug packs) + a PSU header. 12V wall warts can vary in voltage stability, so you can compensate for this with a relatively simple regulator circuit. Though that assumes 3.5″ drives are super finicky about their 12v rail and this is just my first coffee stream of consciousness.

    • Thanks Leon,
      Regarding PD, we thought the same – adds complexity and quite expensive on the side of adapters. But if everyone wants it then we have no choice 🙂
      So far the majority is in favor of the simple input.

      We are considering a varying voltage input.

      • If you keep it simple and limit it to a 12v classic barrel or a bi-pin/tri-pin connector design, you can GET a USB-C PD adapter that’s minimal and offer it to people if they want/need the whole thing. One of the largest problems in the space we’re talking about here is that people want “sexy” and want “cheap” and don’t get that the one or the other precludes the other. X-D

        I want a compelling price with something that’s making as good a showing as you’re seeing with the SSDs there. It needs to be a basic box with drive “sliders” that boots itself off of something other than the array. One of the problems with most of the inexpensive array solutions of the past is that the OS resided on your store. Lose the array, lose the whole of the box. Laaaaame.

  4. We work with Bitscope Blades and for the single blades they had a barrel connector that could accept between 9V and 48V unregulated, which made it very easy power the Pi’s plugged in to them. The newer cluster blades can handle between 12V and 28V.

    Not sure if this sort of feature would be feasible cost wise, but I thought I’d toss it into the ring.

  5. I think that you should take the lower cost path to start with.
    We all have spare 12V (car) and 19V (laptop) supplies lying around.
    We can build a better v2 solution latter
    3.5″ drives are still much cheaper and bigger than 2.5″ drives or SSD
    There is limited throughput provided by the PCI channel any way.

    Now we just need a nice case to put them in – personally I like the idea of having the disks exposed so that they can easily be pulled/replaced without opening the case. A bit Like the various disk duplicators I have here where the drives sit vertical on the sata connectors and are air cooled. Yeah.

  6. Power consumption, we are looking at less than 50W
    ie: Less than 10W per drive, and less than 10W for the Pie etc

    * 10 A @ 5V – I smell burning connectors
    * 4.1A @ 12V – 60W Available on ebay for less than $20
    * 2.6A @ 19V – Easily achieved with most laptop power supplies

  7. Thanks for asking. I don’t think that its a deal breaker to use USB or a 12V power connector. I would however, like the option to have both SSD and spinning disks. So, my advice is don’t skimp on input power.

  8. My humble opinion:
    A good quality, powerful 12V PSU is easy to obtain and cheap.
    A 12VDC barrel input looks more “professional”

    Maybe a Desktop version with barrel jack and 3.5″ drives and another Mobile version with PD and 2.5″ SSDs / HDDs ?

  9. I would support 12V power supply backed up with a battery or a UPS = due to unplanned power outages and to prevent data loss.

        • It’s not an enterprise device. POE is more of an Enterprise/Telco solution to things.

          Moreover…unless you’re fielding a Type 3 or 4 injector or switch capable of the same, you don’t have the WATTAGE to do this sort of thing- and that’s a LOT of juice down a Cat-5 that’s only sort-of designed for it… POE’s absolutely NOT magic and I wish people would actually stop to THINK about things before going off and asking about it like this. X-D

      • The thinking is less wires, plugs, etc. The problem that they have is that they’re not thinking in terms of just how much juice they need to field down the lines to get it. HDs, even SSDs burn juice like candy. Expected power requirements for a full RAID setup is in the 30-50 watt range. This goes to a Type 3 or 4 POE Injector or Switch as the prior generations weren’t designed with this sort of abuse in mind. POE was designed to provide something like an IP cam or a SIP Endpoint power without having a PS brick somewhere in the mix to simplify wire up.

        It wasn’t designed to drop a NAS into the mix without it’s concomittant brick.

        • Well, Realy, for me, I would like to put my NAS in a cold place, well, because all that juice makes heat, and I only whand that in winter and where I can’t hear it. And such a place at home means far away from any power socket.
          If I need an AC adapter, I prefer to have it on the same side as the switch, with a type 3,4, or 5 AC to Ethernet adapter, rather than a AC to 12V witch needs AC where I don’t have it, simple as that

  10. Cool project. If it would enable us to create PI4 powered devices like QNAP TR-004, but PI4 based, I would buy two.
    A case project to mount 1 or two of these in a shallow rack (read network rack < 240mm deep) would be awesome.
    If this would be modular, if would be a matter of screwing modules and/or rack ears together, or no ears but rubber feet foor desktop

  11. Only complaint on the questions? No, “all the above,” on the drives supported. Embrace the epic and awe-inspiring power of, “AND!!”

  12. I love my toys as much as the next guy 🙂 but I’d prefer the robust, cheap, 12v supply (that I already have lying around anyway) – PS’s aren’t THAT sexy.

  13. I also think around 19v input will be nice.
    Old and new laptop adapters is easy to find and cheap.

    Intel NUC is running their system at 19v.

  14. For the places with frequent power shortages, definitely people will need some major UPS power solutions.

    However, for the ordinary user a solution that powers off the disks safely in case of power failure, would be a (disk) life savior!
    So some optional connector for an external battery like this:

    Or even better like this:

    would be suitable for everyone acknowledging how dangerous power interruptions are for disks.
    With electric cars getting more and more into the grid, we would have more and more power issues.

    I have a RPi NAS and my biggest issue is to find a dc-dc ups able of powering 60w and the main thing is that if the battery Ah is not enough it will not power the disks properly anyway, so not a proper solution.

    Adding some 4 or 5 BMS (battery management system) elements on the board and making a battery connection is a deal-maker for me 😉

  15. When it comes to power supply to me as long as it gets the job don’t I don’t really care myself. With that said I am going to want to put 4 large capacity drives 8G plus inside the case and I would be very upset if the power supply melts down or I am given instructs like buy a PC power supply and create the connector as so kind of instructions. So if it cost $50 bucks more to add a USB C connector that would support that many drives were the 12v 5A barrel wouldn’t be able to keep up and I have to DIY a PC power supply to supports it power needs than I say go USB C. However if 12v 5A is going to be enough power than I am all for the cheaper barrel adaptor.


  16. Getting a cheap laptop psu or similar is possible for anyone. So 12V or 20V barrel input is the way to go. There is no benefit in usbC power here.

    As for a home nas, sure I want to go with big old reliable 3.5in drives, but accept other have different priorities.

  17. Go for to worst scenarios. Say I would use 4x 3.5″ power hungry hdds and a lot of computing on the cmi4. And I definitely want to just “plug and go” option, being reliable and knowing it will not fail to power shortage or anything similar.
    In this section I just don’t want to worry about wich power supply should I get, I want you guys to sell the perfect option for your product, that I can rely on and trust.



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