A small, power efficient and quiet home server is something I’d love - extra points if the power supply is built in.
I’ve tried a lot of Intel Nucs and they come close. The Nuc9 especially so, as it fits PCI cards.
Runs Debian (Armbian). Provides file shares over SMB, Syncthing, S3 (Minio). Also does some monitoring of other systems via Prometheus scraping of node-exporter. Everything except Samba runs in containers.
With two mirrored 6TB HDDs it has no problem keeping up with the household 1GbE network. Quad A55 cores, 4GB with Zram and it has all the power I need.
After messing with some RPis and Odroids, I went the other way and just got a single used Lenovo workstation off Ebay. After a memory upgrade (with ECC) and adding an SSD for the system disk, it was about $200, or about the same as fully outfitting two higher-end RPi4s. Easily runs a half-dozen dockerized services, with capacity to spare, and takes care of a bunch of ZFS-formatted, mirrored, spinning rust internal hard drives (ZFS on USB disks is... not fun).
It can't live-transcode video above about 720p without stuttering, but then, most of those ARM boards can't either, so I just have to make sure whatever client I'm using can handle native formats for all my media.
Not sure how it is on power use, but I much prefer managing all that stuff on one machine.
Typically I like to use my old laptops as "servers".
They usually get dropped or ran over or screen hinges broken or something like that. Long before the actual hardware inside gets a chance to fizzle out.
They have a lot of advantages in that they are low power, have built-in UPS, small, have a keyboard and display. The disadvantage is that you don't get a lot of storage options. I have some USB 3 attached storage, but I wanted something a little different this time.
Most recently my RPI 4 8GB serving as media server got replaced by my girlfriend's Asus laptop. She knocked it off a table and the corner of the display got smashed in. Now it is running Linux and Kodi, among other things. Can barely see it sitting there under the TV.
A bit better at 4K out then RPI 4, but not by a whole lot. Don't do any transcoding on it, though.
My "Big Servers" for my home lab are 3 ancient HP 1U rack servers. Built a small horizontal rack so they "hang down" instead of sideways and they take up almost no room. They run some high efficiency Xeon processors so I can get away with running them off of one household outlet. I only leave one on and spin up the other two when I need the extra capacity for some project.
Dual socket 8 cores and 72GB of RAM each.
Figured out that if you go and look at Vmware hardware support and get a server that is _just_ one generation older then they are willing to support than these things are dirt cheap on the used market.
If they can't run the latest version of Vmware then nobody wants them. Linux don't care, of course.
I think I spent a total of 600 dollars for all 3 servers, but it could of been a lot less. It's been a while.
I hate dealing with server-grade hardware because the lights out stuff is insecure (100% get one with a dedicated LO network port), dealing with firmware configuration is tedious, take forever to boot up, and dealing with the raid controllers is misery. But it's the cheapest way to get a ton of capacity. Especially if you have a project that wants to use IPMI and such things.
It’s close and the 10gb networking makes it attractive.
However it maxes out at 16gb ram (a Nuc 9 goes to 64) and virtualisation isn’t quite there yet I don’t think. Fusion says it supports the M1 but I don’t get good results.
I’d like esxi or Proxmox on it, but could learn to live with it as is I suppose.
