Mini PC for Home Assistant and Plex: What Actually Matters

Two jobs that want different things

Home Assistant and Plex both run all day on a small box in a cupboard, but they want nearly opposite things from it. Home Assistant needs very little, as long as the box stays up. For Plex, it comes down to the brand of processor.

Home Assistant is a tiny workload. It runs on a Raspberry Pi 4 or 5 with as little as 2GB of memory, according to its own installation guide. What it does need is a machine that stays up for months, boots from a proper drive and sits on Ethernet. It also needs a spare USB port for a radio dongle, the small stick that talks to your smart-home devices.

Plex is easy until something needs converting. When the television can play a file as it stands, that's called direct play, and it costs the server almost nothing. The work starts when the video has to be re-encoded as it plays. A phone on mobile data can need that. So can subtitles that have to be burnt into the picture. That's transcoding, and it's the whole question when you're choosing a box for Plex.

Handing that job to dedicated video hardware, instead of the main processor cores, is called hardware acceleration. Plex's hardware acceleration is built on Intel Quick Sync Video. That's why, for Plex, the processor brand is the decision.

Idle power is the running cost

A server runs around the clock, so what it draws while doing nothing matters more than its peak. Intel rates the N100 at 6W. The Core i5-13500H in the GMKtec M3 Pro gets a processor base power of 45W, rising to 115W in turbo.

Those are ratings for hard, sustained work, not idle figures. But the gap between the two is what matters. A box built around a low-power laptop chip costs little to leave on all year at British electricity prices. An old desktop tower doing the same job costs a good deal more.

The letter at the end of each chip's name tells you which kind it is. The U-series Ryzen chips among our picks (7730U, 7430U, 7330U) are the low-power ones. The H-series chips (Ryzen 7 6800H, Core i5-13500H) are hungrier.

Quick Sync: the one thing Plex asks for

Plex's hardware-accelerated streaming uses Intel Quick Sync Video, which is in all recent Intel Core processors. It also needs an active Plex Pass, Plex's paid subscription. With hardware acceleration, you get more streams at once and, in Plex's words, less power. Without it, every transcode is done in software on the CPU cores. And converting a 4K HEVC file (big, and heavily compressed) is exactly the work the hardware exists for.

AMD is the awkward part. Plex describes its support for dedicated AMD graphics cards as untested and provided as is. For Linux, the engines it lists are Intel, NVIDIA and software. So plan on software transcoding on every Ryzen (AMD) machine here. That's fine for a 1080p stream or two on an eight-core Ryzen 7 6800H. 4K files should be direct play.

Just one of the seven on our shelf is Intel: the GMKtec M3 Pro. Its Core i5-13500H comes with Quick Sync Video, Iris Xe graphics, twelve cores and 16 threads, according to Intel. The Radeon 680M in the GEEKOM A6 and BOSGAME P3 Lite is the strongest integrated graphics among the Windows machines on the page, according to their listings. For Plex transcoding, it's beside the point.

Gigabit is enough, and 2.5GbE is for one job

The GEEKOM A6 and the GMKtec M3 Pro both list 2.5G Ethernet, two and a half times the speed of a gigabit socket. For playback, it changes nothing: a Plex stream to a television is a small slice of a gigabit link.

The extra speed counts when data has to move faster than a gigabit. That happens when the library lives on a NAS (a box of drives on your home network) with its own 2.5GbE port, and you're copying rips across. It also happens when the box shares a full-fibre line faster than a gigabit.

Either way, use a cable. An Ethernet connection is on the list of requirements for every kind of hardware in Home Assistant's guides.

Memory, storage and the second slot

Neither job needs much memory on its own. Memory starts to matter when one box runs both, plus a Proxmox host and a few containers. Proxmox is software that lets one computer run several separate systems at once, and there's more on it below. For that kind of set-up, 32GB in the box earns its keep, as on the BOSGAME P3 Lite. So does a high ceiling, meaning room to add more: 96GB on the GEEKOM A6, and 64GB on the A5 and the M3 Pro.

Mini PCs hold one or two drives, not a NAS's worth. Only the M3 Pro lists a second M.2 slot free, a short 2242 one, for another SSD. A Plex library lives on a NAS or a USB drive. The box itself holds the operating system and the metadata (the artwork and descriptions Plex shows). The 256GB drive counted against the GEEKOM A5 as a desktop. Home Assistant needs so little space that here it's no problem.

Putting Home Assistant OS on bare metal (straight onto the PC, with nothing underneath) costs you Windows. The install writes its image over the internal drive. So the Windows licence on any of these machines is gone the moment you do it. Home Assistant's guide assumes the PC is dedicated to it. It also expects the PC to boot using UEFI, the standard start-up system on modern PCs, with a security setting called Secure Boot disabled.

Fan noise

None of the seven is described as fanless. Going by the listings, the quietest are the low-power machines. The GEEKOM A5 is the quietest combination on the page: eight cores on a low-power chip. The NiPoGi E3B and the ACEMAGICIAN Kron K1 also use low-power chips.

The H-series machines (the A6, P3 Lite and M3 Pro) will use their fans under load. That's what an H-series chip in a small case does. The M3 Pro's listing gives no noise figure.

A Home Assistant box idles nearly all the time. A Plex transcode keeps the processor working hard for the length of a film. So if silence in the room is the point, put the box in a cupboard and let the media come down an Ethernet cable.

Proxmox or bare metal

Home Assistant OS on a PC of its own is the simplest way to run it. It's also the installation type Home Assistant recommends for most users.

You can run it in a plain Docker container instead, which keeps a program in its own sealed-off space on top of another system. But that costs you the add-ons, which Home Assistant has renamed apps. Add-ons are how Z-Wave and Thread are provided, and those are two of the radio standards smart-home devices use. So if you virtualise (run several systems on one box), run the full OS image as a virtual machine, or VM. That's a whole computer simulated in software, and Home Assistant documents how to do it.

Plex is the sticking point. Hardware-accelerated streaming isn't possible inside a virtual machine, its documentation says. The host (the system running underneath) doesn't expose the video hardware to the guest (the VM). A Docker container works normally, as long as it's given access to the graphics device.

So if it all goes on one box, here's the layout. Proxmox runs directly on the hardware. Home Assistant OS runs in a VM. Plex runs in a container that can see the graphics device. It also means passing a Zigbee stick (the radio dongle from earlier) through to the VM. And it leaves you three things to keep updated. Two small boxes isn't a silly answer.

The dongle and the extension lead

This is the part a mini PC gets wrong out of the box. The Zigbee stick should never go straight into the back of it.

All computers and the devices plugged into them give off the interference that degrades a 2.4GHz radio, according to Home Assistant's Zigbee documentation. It names USB 3.x ports and devices as the real-world culprits.

Its advice is to use a USB extension cable, and to plug the adapter into a USB 2.0 port or a powered USB 2.0 hub. It also says to keep the adapter away from USB 3.0 devices, Wi-Fi access points, power supplies and electrical cables.

So put the stick on a long, shielded extension lead, out in the open and well away from the case. Treat a Z-Wave stick the same way.

A used OptiPlex Micro, a new N100 box or a Raspberry Pi

There are three things a forum will tell you to buy instead. The first is a used Dell OptiPlex Micro (or a Lenovo Tiny or HP Mini) with an Intel Core chip, which gives you Quick Sync. What to check is the chip's generation. Plex advises fifth generation or newer for the best results, and seventh or newer for HEVC encoding. Home Assistant's guide expects UEFI, and says most systems from the last ten years boot that way. What you give up is the warranty and the low power draw.

A new N100 box is the second forum answer, and Intel's numbers explain why. The N100 has a 6W rating, four cores and Quick Sync included. It takes up to 16GB of memory, on a single channel. The N150 that followed keeps the same four cores and 6W rating. That makes an N100 box a Plex transcoder and a Home Assistant host in one. But the single memory channel and the 16GB ceiling rule it out as the Proxmox box that does everything. None of the seven on our shelf uses one.

Then there's the Raspberry Pi. Home Assistant runs happily on a Pi 4 or 5 with 2GB or more, from a microSD card, and for that job alone it's fine. For Plex, it's direct play only. The hardware engines Plex lists for Linux are Intel and NVIDIA, so every transcode on a Pi is done in software.

Where the seven picks fit

For Plex, or both jobs on one box, the pick is the GMKtec M3 Pro. It has Quick Sync, twelve cores, 2.5G Ethernet and a second M.2 slot. The downsides: it ships with 16GB, so a box that runs everything will want more, and its H-series chip will use the fan under load.

For Home Assistant alone, the GEEKOM A5 is the quiet eight-core answer. The Kron K1 does the job for less, with four cores, and has the highest owner rating of the seven. The NiPoGi E3B has six cores and the most owner ratings on the shelf, but its 16GB of memory is soldered to the board, so it can't be upgraded later.

The Apple Mac mini is on the shelf too, and it's a different proposition. It runs macOS, its memory and storage are fixed at purchase, and its Ethernet is gigabit. Plex Media Server runs on a Mac, and Home Assistant runs in a container on one, but the Proxmox route above is a Linux route, and this isn't the box for it. Buy the Mac mini because you want a Mac on the desk, not because you want a server in the cupboard.

The GEEKOM A6 and BOSGAME P3 Lite are the strong Windows desktops here, and the A6 is the 2.5G Ethernet box, which counts if your library lives on a NAS with its own 2.5GbE port. They're also the wrong tool for a headless server, one that runs with no screen or keyboard. You'd be paying for Radeon graphics Plex can't use, and a memory ceiling a Home Assistant box will never approach. If the machine is also your desktop, that changes. The full comparison is on the mini PCs page.

Sources

• Home Assistant: Generic x86-64 installation guide (UEFI and Secure Boot, boot medium, dedicated PC, recommended installation type)
• Home Assistant: installation overview and hardware options (Raspberry Pi 4 or 5 with 2GB, Ethernet, virtual machines, Container without apps)
• Home Assistant: Zigbee Home Automation integration, interference avoidance
• Plex Support: Using Hardware-Accelerated Streaming
• Intel: Core i5-13500H product specifications
• Intel: Processor N100 product specifications