Hardware
I constantly tweak my hardware setup. These are my notes. TL;DR: Unifi for network, Hardkernel ODROID for NAS servers, Radxa Zero for ultra low power console and relay management.
Network & Primary Servers
9U WALL-MOUNTED RACK
┌──────────────────────────────────┐
9 │ ≡≡≡ ≡≡≡ HDDs / SBC ▒▒▒▒▒▒ │
├ └──────────────────────────────┘ ┤
8 │ │
├ ≡≡≡ ≡≡≡ ┤
7 │ ≡≡≡ ≡≡≡ HDDs / SBC ▒▒▒▒▒▒ │
├ └──────────────────────────────┘ ┤
6 │ │
├ ◌ ◌ ◌ ◌ 8-Outlet UPS ◌ ◌ ◌ ◌ ┤
5 │ │
├──────────────────────────────────┤
4 │ Lockable Drawer │
├──────────────────────────────────┤
3 │ Router [┬] [┬] │
├───────────────────────────│───│──┤
2 │ [┬] [┬] [┬] [┬] Switch [┴] [┴] │
├──│───│───│───│───────────────────┤
1 │ [┴] [┴] [┴] [┴] Patch Panel │
└──────────────────────────────────┘
Slot Part ────┬─────────────────────────────────── 9 │ SBC + WD Red Pro HDDs, 1U shelf 8 │ -- 7 │ SBC + WD Red Pro HDDs, 2U shelf 6 │ -- 5 │ CyberPower UPS CP1500PFCRM2U 4 │ 1U 12" Lockable Drawer 3 │ Unifi UDM Pro (Router) 2 │ Unifi USW Pro Max 16 PoE (Switch) 1 │ Cable Matters 24-port Patch Panel 0 │ Tecmojo 9U, Swing Gate, 18" Depth
All the Ethernet cables in my house terminate in a small closet. On the wall I’ve got a 9U rack with the core of my network stack as well as my main single-board computer (SBC) servers.
The Hardkernel ODROID series is my favorite server platform. I elaborate on the H4 Ultra and H5 systems below, but in short these give me the same capabilities of my old full-depth rack servers at a fraction of the wattage and hardware cost.
General Purpose Server: ODROID H4 Ultra
ODROID H4 Ultra ─┬───────────── │ ├─ CPU: Intel i3-N305 │ ├─ RAM: 64GB DDR5 │ ├─ SSD: 1TB │ ├─ HDD: 22 TB ─┐ │ ├─ Mirror ─┐ ├─ HDD: 22 TB ─┘ │ │ ├─ 48 TB Pool ├─ HDD: 26 TB ─┐ │ │ ├─ Mirror ─┘ └─ HDD: 26 TB ─┘
Qty Physical Part ───┬──────────────────────────────────── 1 │ ODROID H4 ULTRA SBC 1 │ Intel i3-N305 CPU w/ Quicksync 1 │ Crucial 64GB DDR5 RAM 2 │ WD Red Pro 26 TB HDD 2 │ WD Red Pro 22 TB HDD 1 │ Samsung SSD 970 EVO Plus 1 TB Qty Virtual Part ───┬──────────────────────────────────── 1 │ FreeBSD - Operating System 1 │ ZFS - File System
My main system is the ODROID H4 Ultra. It is the platform that convinced me SBCs could take on server roles. To give you a feel for why I love this system, consider the load I’m running and I never notice a slowdown or lag:
- Syncthing watching about 30 TB of data
- Restic accepting backups from a handful of people
- Plex serving media
- Desktop FreeBSD running with VNC access
- Dozens of small apps for IRC, email, news
- ZFS encrypted datasets with hundreds of snapshots managed by Sanoid
And most impressive, its 8 cores comes in under 15 Watts of power consumption. I highly recommend this device. I run FreeBSD on it and everything just works.
Backup & Media: ODROID H5
ODROID H5 ─┬─────── │ ├─ CPU: Intel i3-N300 │ ├─ RAM: 64GB DDR5 │ ├─ SSD: 8TB │ ├─ HDD: 20 TB ─┐ │ ├─ Mirror ─┐ ├─ HDD: 20 TB ─┘ │ │ ├─ 40 TB Pool ├─ HDD: 20 TB ─┐ │ │ ├─ Mirror ─┘ └─ HDD: 20 TB ─┘
Qty Physical Part ───┬──────────────────────────────────── 1 │ ODROID H5 SBC 1 │ Intel i3-N300 CPU w/ Quicksync 1 │ Crucial 64GB DDR5 RAM 4 │ WD Red Pro 20 TB HDD 1 │ 8 TB WD_Black SN850X Qty Virtual Part ───┬──────────────────────────────────── 1 │ FreeBSD - Operating System 1 │ ZFS - File System
When I saw that Hardkernel announced the H5 in May 2026, I instantly bought one. For me, it was the final component that allowed me to fully migrate away from the full-depth 15U rack in my garage (see end of this article).
This device is very similar to the H4 Ultra with a few key difference: Intel i3-N300 processor, 4-port on-board SATA replaced by 6-port SATA via NVMe expansion card, and a single 10G ethernet port. This whole package runs at about 7W and idles closer to 2W.
This system runs Plex and acts as a full data copy of my H4 system.
DIN-Mounted SBCs
Just above the 9U rack I’ve got a few smaller SBCs mounted on DIN rails. Only one has a proper 24/7 role. The others are for experimentation. All are PoE powered.
Wall-Mounted DIN Rails
════════════════════════════════════
2 140mm Radxa Radxa
▔▔ Fan ▔▔ Cubie A7S ▔▔▔ Zero 3E ▔▔
════════════════════════════════════
════════════════════════════════════
1 Radxa Raspberry
▔▔▔▔▔▔▔▔▔▔▔ Zero 3E ▔▔▔ Pi 5 ▔▔
════════════════════════════════════
Rail Part ────┬─────────────────────────────────── 2 │ Fan: AC INFINITY 140 mm │ SBC: Radxa Cubie A7S │ SBC: Radxa Zero 3E 1 │ SBC: Radxa Cubie A7S │ SBC: Raspberry Pi 5
Console & Relay Management: Radxa ZERO 3E
Radxa ZERO 3E ─┬─────────── │ ├─ CPU: Quad-core Cortex A55 │ ├─ SoC: Rockchip RK3566 │ ├─ RAM: 2 GB LPDDR4 │ └─ µSD: 256 GB
Qty Physical Part ────┬─────────────────────────────────── 1 │ Radxa ZERO 3E 1 │ DIN Rail Mount Breakout Board 4 | Teyleten Robot DC 3V/3.3V Relay 1 │ SanDisk 256 GB microSDXC
I wanted the lowest power system that can run Linux or FreeBSD and act as a BMC alternative. The Radxa ZERO 3E fits this space perfectly. I have it running DietPi (Debian). I’d prefer FreeBSD, but the Linux support for the 24-pin GPIO is better and DietPi does a nice job of power optimization compared alternatives like Armbian. It gives me serial console access to the other systems nearby by connecting UART pins between systems, and it is wired to optocoupler power relays that allow me to perform the equivalent of a physical button press on the nearby systems (i.e., I can do a hard reboot remotely if necessary). This tiny thing runs around 1 Watt, 2 max.
Test Boards
Other SBCs I have are for testing and experimentation without impacting the aforementioned SBCs.
The Radxa Cubie A7S is an interesting one as it uses the Allwinner A733 SoC. As of Linux 7.2, it doesn’t have mainline support in Linux yet, but with 8 ARM cores and a RISC-V co-processor, I’ll be curious to see how it performs as it mainlines.
The second Radxa Zero 3E I use to experiment with FreeBSD, which mostly all works on the RK3566, but has a few rough edges.
The Waveshare ESP32-S3-ETH device was originally purchased to control UART consoles and remote power-on/off events. I ultimately went with the Radxa ZERO 3E for this problem space, so this has become more of a toy.
The RPi 5 and RPi Zero 2W spend most of their time powered off these days. Since 2022 or so, I find RPi increasingly less interesting compared to alternatives.
Test Equipment
Once you start connecting wires to electrical sources, you really should invest in electrical test equipment. I purchased a Fluke 117 Multimeter and love it. It’s not my first multimeter, so I’ll highlight a few things that stand out for me.
- One-handed use. The dial exposed on the left side of the device makes it very easy to rotate with your thumb.
- Non-contact voltage detection. Just hover over where you think a live wire might be and an alarm triggers if one is detected.
- Modular leads. Many cheap multimeter have the leads hard-wired. With a modular setup, you can get leads that, for example, easily fit into a female GPIO slot, clamp onto a hard-to-reach wire in a wall, etc.
- Auto AC/DC voltage selection and many other nice features that maximize utility and simplicity.
Rack 2: Full 24” Deep Rack
I moved from PC towers to a rack setup in 2013, but as of May 2026 I’ve decommissioned these components in favor of the much smaller, cheaper, and capable SBC components above. The rack servers have served me well over the years. But these days, most things that fit in a 24” rack are overpowered both in terms of capability and electricity consumption. The original thing that attracted me to this space was the ability have a chassis with 8-12 hot swap HDDs. There was a time when one server would have all these slots full. With modern HDD capacities, 4 HDDs are more than enough for my needs, and that likely shrinks to 3 or maybe even 2 HDDs by 2030. For now, they sit offline. I’ll probably sell or give them away at some point.
15U ROLLING RACK
┌─────────────────────────────────┐
15 │ ↗ Fiber Switch │
├ Shelf ↗ Ethernet Switch ┤
14 │ (Front) ↗ (Rear) │
├─────────────────────────────────┤
13 │ │
├ Drawer ┤
12 │ │
├─────────────────────────────────┤
11 │ │
├ Supermicro Server ┤
10 │ │
├─────────────────────────────────┤
9 │ │
├ Supermicro Server ┤
8 │ │
├─────────────────────────────────┤
7 │ ════════════ Cover ════════════ │
├─────────────────────────────────┤
6 │ ════════════ Cover ════════════ │
├─────────────────────────────────┤
5 │ │
├ ┤
4 │ Drawer │
├ ┤
3 │ │
├─────────────────────────────────┤
2 │ │
│ ◌ ◌ ◌ ◌ ◌ UPS ◌ ◌ ◌ ◌ ◌ │
1 │ │
└───┬─────────────────────────┬───┘
Ō Ō
Slot Part (Front-facing) ────┬────────────────────────────────── 15 │ -- 14 │ 2U Shelf 13 │ -- 12 │ 2U lockable drawer 11 │ -- 10 │ Supermicro 825TQC-R740LPB Chassis │ ├ Supermicro X12STH-F Motherboard │ ├ Intel Xeon E-2324G │ ├ 4 x 16 GB DDR4 UDIMM ECC RAM │ └ Intel X710-DA2 Fiber Network 9 │ -- 8 │ Supermicro 826BEC1C-R920LPB Chas. │ ├ Supermicro X12STH-F Motherboard │ ├ Intel Xeon E-2388G │ ├ 4 x 32 GB DDR4 UDIMM ECC RAM │ ├ Nvidia Mellanox ConnectX-4 Lx │ └ Supermicro AOC-S3008L-L8e HBA 7 │ Cover on blank slot 6 │ Cover on blank slot 5 │ -- 4 │ -- 3 │ 3U lockable drawer 2 │ -- 1 │ Schneider/APC Smart-UPS X 1500 0 │ 15U Rolling Rack, 24" Depth Slot Part (Rear-facing) ────┬─────────────────────────────────── 15 │ UniFi 24 PoE Switch 14 │ UniFi Fiber Switch
