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Lampone314
Posts: 1
Joined: Fri Nov 08, 2019 11:01 am

Rpi4 questions about power supplies and performance for a media server and home automation hub

Sat Nov 09, 2019 11:33 am

Hello guys, first of all sorry if it's the wrong section but I have multiple questions and I wasn't sure where to post, I can make individual threads if it's better.
I'm planning on buying a Raspberry Pi 4 4GB and relative accessories taking advantage of the Chinese 11-11 and Amazon's Black Friday (and maybe Melopero, the official Italian Raspberry reseller). My goal is to use a single board for multiple purposes:
-a media server using Plex or Kodi, for content at 1080p at 60Hz or less without transcoding, to 1 or 2 clients at a time
-a basic NAS for personal use, at least on the beggining just for the local network
-a home automation hub with something like hass.io and a radio module (RFM69) for the MySensors project
-a Pi Hole DNS sinkhole

I have a some questions:
- Is it possible to run all this things on the same Pi or the performance won't be enough? I can sacrifice something and maybe get another Pi in the future.
- Can I use Raspbian with docker containers if needed or should I expect conflicts or other limitations? I wanted to boot from a flash drive but I read that it's not possible on the Pi 4 yet but I would at least move /root on a flash drive faster than the sd.
- How should I handle power?
Let me explain this last one. I intend to fit the whole project inside an ITX case using adapter plates (that I would build), I have found a used Coolermaster Elite 130 for cheap in a local site but I am waiting to solve the power supply issue before buying. I have a 2.5" drive and a sata to usb cable and I plan to add more drives down the line so I was thinking of putting an active USB hub inside the case. For the cooling I plan to use a passive heatsink and the case fans, they're 12V but they're big enough that at 5V the airflow should suffice. So the options are:

-the official power supply and a separate power supply for the hub but then I would have to manage 220V AC inside the case and a mess of sockets and wires, the fans would be at 5V and I could not use 3.5" drives

-a 5V power supply of those that are used for led strips (somehting like this https://www.amazon.it/dp/B07DQKM9P7/) but they're not very reliable and I don't know how I could stabilize it, like before the fans would be at 5V and I could not use 3.5" drives

-a 12V power supply similar to the previous one and a buck converter, I would lose in efficiency but the buck converter should stabilize the output of the power supply, I would run the fans via a PWM controller and I could use 3.5" drives if I wanted to

-an ATX power supply, not very efficient and I'm not sure how reliable, I have a couple of old ones that work well but they're old and cheap and not even rated

-something that I havent thought of yet

I haven't settled on any specific model for the hub because I want to choose the power supply configuration first but I've read that some may have issues of backfeed, there are lists of known good models but the're quite outdated, should I worry or any decently built hub would work?

I am not a complete beginner with Linux or electronics but I'm no expert and I have never had a Raspberry Pi so I chose to post in the beginner section, I'm not so sure about it now but I'm also new to the forum so tell me if I made the wrong decision.

Thank you for reading this far, If I made mistakes please correct me, I'm here to learn. Any help is appreciated.

dustnbone
Posts: 201
Joined: Tue Nov 05, 2019 2:49 am

Re: Rpi4 questions about power supplies and performance for a media server and home automation hub

Sat Nov 09, 2019 6:39 pm

If what you're after is lots of reliable 5V I'd recommend something like this

https://www.sparkfun.com/products/14098

That ones got some voltage adjustment so you could boost it to 5.1 or 5.2V to keep the Pi happy.

You could probably get by with a much smaller one for your application, look for an industrial electronics supplier in your area and see what they have.

Mean Well is a very established manufacturer in their field. They basically only make power supplies. I've used them for various industrial installations over the decades and cannot recall one ever failing me.

PhatFil
Posts: 1632
Joined: Thu Apr 13, 2017 3:55 pm
Location: Oxford UK

Re: Rpi4 questions about power supplies and performance for a media server and home automation hub

Sat Nov 09, 2019 8:19 pm

fwiw i used an old pc case to house my p3b nas/pihole server (I host the home automation on a pi-0-w closer to the bluetooth sensors upstairs) i use a small 5v 3a switching psu for the Pi , and then use the pi to control a smart switch controlling the atx psu which provides power to the usb hab and the old 12v 3.5" hdd enclosures i have.

My disks are not needed very often so i power up the atx psu on demand, it adds a couple of minutes to the initial delay, but it keeps power consumption and internal heat build up in the fanless case well within comfort levels, a pi4 may not run as cool....

boyoh
Posts: 1419
Joined: Fri Nov 23, 2012 3:30 pm
Location: Selby. North Yorkshire .UK

Re: Rpi4 questions about power supplies and performance for a media server and home automation hub

Sun Nov 10, 2019 12:23 am

First get a understanding of basic electronics
And power supplies, There are lots of books on
Power supplies. You seem to know what you
Want, put unable to put it in to practice
Break your projects down, pick the simplest
Fist and see if you can complete that first

Regards BoyOh
BoyOh ( Selby, North Yorkshire.UK)
Some Times Right Some Times Wrong

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