I’ve been dithering for too long, it is time to take action!
I want a NUC but the choice is a little overwhelming. What aspects of the hardware are likely to have the most impact on HA?
e.g.
Memory (amount and type)
Processor speed
Number of cores
… anything else?
Alternatively what model do you have and do you have any real-world experience you can offer?
e.g.
HA start up speed
Lovelace responsiveness
… anything else?
Thanks 
I have a gigabyte Brix, this one
It’s massively overpowered, currently runs Ubuntu headless, with 2 virtual Ubuntu servers (I offload their storage to my nas for ease of backup). Both vms run docker, one is all my ha stuff - home assistant, deconz, nodered, mqtt, telegraf. The other is management stuff, portainer, telegraf, influxdb, grafana.
Plenty of headroom for other vms to play, try things out, do a bit of development or testing etc.
I have a ,7 gen i5 with 16 gb memory. It is way overkill for only HA but I also run a xeoma cctv server and a traccar server. You cant compare speed and stability if you use pi now. I have about 20% cpu load and all is very very fast. I run HA on ubuntu and docker.
The model I have is a few years old right now, but I went with a relatively cheap Celeron NUC (~$120 at the time I think) and added a 256 GB SSD and 8GB of RAM. Unless you have some CPU-intensive activities going on (Plex?), you don’t need anything more powerful than this. Its better to run only home automation on one device anyways if you can support it. Even just being a Celeron, the difference was huge coming from an RPi3. Startup times are very quick. The slowest part is waiting for Z wave to be ready which is really a function of that protocol and not the machine.
I’m running Proxmox with an Ubuntu Server VM with Docker that runs Hass, Node Red, Mosquitto, and all of the other HA-related containers. I run a few LXC containers in different VLANS on the same box which is why I went with Promox, but you would be just fine running Ubuntu Server w/ Docker bare metal.
I pretty much have the same as @Yuran but a newer model. Overkill but I have no slowdown issues.
Thing you need to decide:
what processor: i3, i5, i7
Do you want to use a normal ssd or the laptop style ssd? laptop ssd is smaller and doesn’t require cables. There are 2 styles of nucs, one that supports both style ssd’s and 1 that supports only the laptop version. I bought the one that supports both styles. It’s physically larger.
Buy the nuc without an operating system (I think they are called nuc kits). You’ll just be putting linux on it anyways.
I’m running
i5, 256Gb M2 ssd, 16gb ram. I purchased the i5 version w/o the components built in and bought the ssd and 16 gb ram separately. Cost about $600 when all said and done for all components. My setup is overkill but it runs a ton of shit on top of just HA, including video facial recognition.
EDIT: Also, if you can’t tell, the processor type is built into the model number name:
NUC8I5BEH
^^
||
i5 = i5 processor
EDIT2: I’m not home but I’m pretty sure I bought NUC8I5BEH
I fully agree. I have nine security cameras so I wanted some more power.
I just recently put my small server together. I will be using it for HA and also for surveillance video (still testing different software’s - can’t pick one…).
Here is my build:
InWin Chopin Case + PSU
Gigabyte B450 I AORUS PRO WIFI
AMD RYZEN 5 2400G
Kingston Technology HyperX Fury Black 16GB 2666MHz DDR4
MyDigitalSSD BPX 80mm (2280) M.2 PCI Express 3.0 x4 NVMe MLC SSD (240GB)
So the build is overkill - but I like it.
If you aren’t using anything that is intensive, you can build it much cheaper.
8GB is probably enough RAM, get an embedded CPU+MB, and don’t go ITX.
This would probably cut the cost in half.
If you are comfortable putting everything together yourself, you can do this cheap I would say.
I have an i5 Intel NUC Kit NUC7i5BNHX1
with a 480 GB SSD and 8GB of RAM with Ubuntu headless server, very overspecced for just HA, but I run Plex on there too.
Everything is great speed wise for HA restart times and for everything in HA, even when Plex is doing its stuff.
Only negative thing for me is that Bluetooth device tracking does not work very well at all and so far I have not got to the bottom of it.
If you’re looking to do any machine learning image or face recognition I’d highly recommend a CPU with the AVX2 instruction set since things like tensorflow and facebox etc are generally compiled with it as a dependency.
I bought the NUC8I3BEH, i3-8109U with a WD Green 240GB M.2 2280 SATA and Corsair Vengeance 8GB SODIMM DDR4 2400MHz. I am using Ubuntu 18.04 and Docker CE with Portainer. Portainer gives a GUI to Docker. I have a simple setup, nothing fancy and it’s working really well. Overkill, but I might use VM and experiment with the NUC ontop of the hassio install.
Have a look at this review:
Coffee Lake i3 NUC Review (NUC8i3BEH)
In regards to the NUC models out there - are the fanless models the way to go? Or are there drawbacks with them?
Same over here. Once you’re happy with your home automation setup, you might want to jump into other things like traccar or paperless. Don’t go too short on resources in the beginning. Will be way more expensive later on to upgrade or add a second machine.
I recently built my own nuc with a ASRock j4105 8 GB ram and a 250gb SSD. HA is much more responsive. The board I used is fanless so while it sits in the middle of the house next to the TV, you can’t hear it. This was very important to me. I have built enough htpcs (hence the user name) to know that there are times you don’t want the whir of a fan.
Have you looked at Xeoma as camera server?. The best I have ever seen. Not free, there is a one time licence fee per camers, but it is worth every euro.
My 8th Gen i3 has a fan, but I’ve never heard it. They’ve put in a larger fan apparently, so it’s quieter as it does not have to spin as fast. I had to look at a review to confirm it has a fan.
I’m using a 5th gen NUC with a Core i3. Added a spare 4GB RAM stick, and a spare 128GB m.2 SSD. It’s fanless and running like a champ. Plenty of headroom for anything I’ve thrown at it.
Thanks everyone I really appreciate the answers, there is some great advice and information here.
But, I’m getting greedy…
I have a follow up question How to choose an operating environment for a NUC?
I personally have lubuntu (linux) on my nuc and hassio etc running via dockers.
I chose lubuntu as it is a lighter version of the full blown ubuntu.
I have a NUC7CJYH - the most powerful celeron based one… much cheaper than i3 or i5 etc with a 240gb SSD and 8gb RAM.
I was not/am not planning on running cameras so an i3 seemed like overkill and was out of my price range.
It really depends on what you want to run. I run hass.io with a bunch of addons… I think I have around 26 docker images/containers. Not all are Home Assistant related. It doesn’t even break a sweat.
I just setup one of these with 8G Memory and a 120G SSD for about $230 US. You don’t need a lot to run what we do and I am running more on it now. Using Ubuntu 18.04 Workstation with Docker. I am very happy with it, did a write up on it here.