As openHAB2 is working almost well on a raspberry3, it’s more a question of the other software, such as “a few databases” 
Think about 2GByte for openHAB2 plus another 2GByte for a MySQL database (should suffice for private usage)
So 8GByte RAM is more than sufficient. As of processors, anything will fit (given that it’s a current 64bit processor) and the main thing is to find a power-saving model, because the computer will run 24/7.
1 Like
I agree with you @Kim_Andersen , I was just thinking about the one you mentioned vs the cheapest nuc, f.eks NUC6CAYH which starts from 130e locally (without ram and ssd).
That is Intel NUC Celeron J3455 on 1.5 GHz, and as @Udo_Hartmann says, compared to pi which works just fine, I am sure this cheapest nuc will do all it is being asked to. Or would it?
(I will order one cheapest soon, so please let me know if some upgraded version is more suitable 
(power consumption is not priority) )
The J3455 CPU NUC should be good enough for openhab. But I have never tried anything like that.
I think I would hate it simply because of its lack of CPU cache and use of DDR3 these days, wether or not I´ll ever going to need it to run openhab. Thats just the way I am 
1 Like
That is a good point, especially buying ddr3 in 2019.
However, considering the 100e price difference, I can purchase 4tb storage for my other nas server
Then the choice goes from “the best” to “good enough”
Here in Denmark:
The NUC J3455 is priced 146euro
The NUC J5005 is priced 186euro.
Thats 40euro in differences?
Both need RAM and Hardrive.
I wouldnt have any second thoughts about the choise between them. I would spend the 40euro extra and never look back. No matter if I need it or not 
Ofcouse, if you can spend the extra 40euro on something else, which will give you something better, then thats what you should do.
I run openHAB in NUC as well. What I can recommend is to run openHAB on Proxmox VE.
Proxmox VE is open-source server virtualization environment (debian distro + KVM hypervisor + nice web GUI). Basically everything can be done via GUI, so for new users it should be rather easy to use as well.
What is great in Proxmox, is that is also support scheduled snapshot (live) backups out of the box without need to shutdown the VM.
Even Proxmox is very lightweight and most probably run well also on cheapes NUC, I recommend to buy little bit better than just cheapest one.
My NUC7i3BNH is overkill for openHAB only, but I run some other VMs as well. My NUC support both M.2 and 2.5" drives and I have installed proxmox on M.2 SSD and all VMs to other.
There is a guide in this forum how to install Proxmox VE and openHAB
1 Like
I have never used any kinds of WM´s before… I just buy more computers and use it for single stuff. Expensive, yes, but it makes it abit more easier for me to comprehend
Virtualisation is a really nice and cheap technique to improve usage and workload of hardware.
Proxmox is free of charge if you don’t want support. if the system is growing, it’s possible to build a datacenter by using 3 or more real computers. A datacenter is able to run virtual machines (without real hardware) on every node, failover is built in
Indeed a big adventure park, but openHAB is just one fraction of services to run at such a datacenter…
I was actually planing to run single VM on it (as discussed deeper in my other post here Intel NUC vs Laptop for (single) VM running OpenHab and other automation related services)
That way I can easily backup entire system, because I am quite clumsy. Although I love Ansible deployment as Rich suggested on that other post. I use it on my workstation on virtual machines to test things out.
@Kim_Andersen not sure why in norway price difference is 80e between the two (ram is almost the same, few euros there as well). I will sleep on it
P.S. you should try Virtualisation if you never did, just spin some vagrant machine on your desktop and see how you like it, ability to take snapshots and rebuilt machine in 60s when testing is priceless for me (probably because I do not know what I am doing with linux, so most of the time I am just guessing)
Real benefit comes from easy backups. If you screw accidentally your openHAB env or after update you meet any problems, it takes couple of minutes and your environment is up and running again.
true one can use dockers to backup services, but you can use both, docker for per-service backup, and also vm for entire system backup (which I think is important for openhab and home automation in general, as it is quite complex system with a lot of thing happening)
Many (many!!) years ago I tried something… I think it was one of the first versions of WMware… I dumped it cause it was too difficult to get access to peperials, USB´s, drives etc…
But I like the idea to run several indepent systems on one hardware devices. I just hate struggling to get even simple things to work… (hmm, I probably never should have startet on openhab then .
I suspect it is much easier now. I run on ESXi and have had no problem mounting USB devices inside my VMs. That was the easiest part to work with in my setup.
Probably… I just havn´t had the patience to try again. Found it easier to just buy yet another computer 
Just as another datapoint, I have a NUC8i5BEK with 16gb RAM and 512GB Samsungs 970+ SSD running at ca. 3.3W in idle mode (headless). I know it’s overkill, but it does allow to test stuff faster and makes UIs with graphs (integrated or grafana) on tablets and mobiles more responsive.
Hi all i think this is related to subject , what ever platform you take…
I see the topic mostly becoming a hoky war 
, let me throw a piece in. I am running OrangePi Plus2e, chose it due to dimensions and RAM size (2gb). My Android experience tells me Java is always ready to eat more mem.
Emmc size turned out to be good enough for raspbian + openhabian install. Works fine. Though it’s a new install with uptume only about a week.
Takes a bit long t boot up, but does not feel sluggish in operation.
This looks quite interesting, except for the need to create an individual power supply:
What do you think?
I am running OpenHab on Allwinner H5 based Nanopi K1+ I have dozen of Z-wave devices and it seems an overkill.
OpenHab should run on any single board computer under Armbian, selection is quite big. Best thing there is - you don’t need to do anything. System is perfectly optimized for running from SD card: wear-out is cut down to minimum out of the box, system is secure, stable and supported, installation is menu driven.
Except the way oh does logging and persistence is usually orders of magnitude more than what even a typical non-optomised OS would do.
Also, not all boards are created equal. I have a BananaPi running Armbian and the list of things that don’t work like BT is quite long and if you try to do anything that requires a lot of of CPU such as, for instance, start OH, it over heats and freezes up.
I can’t therefore recommend just any old SBC. If you go outside the big players, do your homework.