Intellihome
Raspberry Pi
What it is: An ARM single-board computer from Raspberry Pi Ltd. For smart homes and homelabs it works as a small, low-power server, e.g. for Node-RED, Zigbee2MQTT or umbrelOS. Current models are the Raspberry Pi 4 Model B and the Raspberry Pi 5.1
Raspberry Pi 4 vs. Raspberry Pi 5
According to the official product pages:1
| Raspberry Pi 4 Model B | Raspberry Pi 5 | |
|---|---|---|
| SoC | Broadcom BCM2711 | Broadcom BCM2712 |
| CPU | 4× Cortex-A72, 1.8 GHz, 64-bit | 4× Cortex-A76, 2.4 GHz, 64-bit, crypto extensions |
| Cache | – | 512 kB L2 per core, 2 MB shared L3 |
| RAM | 1, 2, 3, 4 or 8 GB LPDDR4-3200 | 1, 2, 4, 8 or 16 GB LPDDR4X-4267 |
| GPU | VideoCore, OpenGL ES 3.1, Vulkan 1.0 | VideoCore VII, OpenGL ES 3.1, Vulkan 1.3 |
| Ethernet | Gigabit | Gigabit |
| PoE | via PoE HAT | PoE+ via PoE+ HAT |
| Wi-Fi / Bluetooth | 802.11ac 2.4 + 5 GHz / BT 5.0, BLE | 802.11ac dual-band / BT 5.0, BLE |
| USB | 2× USB 3.0, 2× USB 2.0 | 2× USB 3.0 (simultaneous 5 Gbps), 2× USB 2.0 |
| PCIe | – | PCIe 2.0 x1 (M.2 HAT for NVMe) |
| Storage | microSD | microSD (SDR104), NVMe via M.2 HAT |
| Video | 2× micro-HDMI 4Kp60 | 2× HDMI 4Kp60 with HDR, 4Kp60 HEVC decoder |
| Power | 5 V / 3 A via USB-C | 5 V / 5 A via USB-C with PD (27 W supply) |
| RTC and button | no | RTC (external battery), power button |
| Operating temperature | 0–50 °C | not stated |
| Production guaranteed until | at least January 2034 | at least January 2036 |
Boot and storage
- On both the Pi 4 and Pi 5 the bootloader lives in on-board EEPROM, not on the card. Boot media order is set by
BOOT_ORDER; the default0xf41tries microSD, then USB, and repeats.2 - The Pi 5 supports NVMe via the M.2 HAT+, which turns the PCIe connector into an M.2 slot. NVMe boot is enabled in
raspi-config(Advanced Options → Boot Order).2 - USB boot works on the Pi 4 and newer once USB is in
BOOT_ORDER. A Pi 5 with a 3 A supply has USB boot disabled untilusb_max_current_enable=1is set inconfig.txt.2 - Bootloader updates: the
rpi-eeprom-updateservice at startup,defaultorlatestchannel inraspi-config. The Pi 5 has A/B EEPROM updates, so an interrupted update won't brick the board.2 - Synthesis: microSD cards have limited write endurance. A server with a database, logs and Docker containers writes constantly, so NVMe or a USB SSD is better for production.
Power and cooling
- Pi 4: 5 V / 3 A (15 W) via USB-C. Pi 5: 5 V / 5 A (25 W). With a 3 A supply the Pi 5 limits USB current to 600 mA, fan included.2 An external disk or USB Zigbee adapter may then not get enough.
- Overheating: the cores throttle progressively from 80 °C, with a hard limit of 85 °C.
vcgencmd measure_tempshows the temperature.2 - The Pi 5 fan (Active Cooler or the official case) starts at 50 °C (30 %) and runs at full speed from 75 °C.2 Synthesis: for a server running 24/7 cooling is worth it; without it the Pi slows down under load.
- The Pi 5 power button wakes the board from standby. The RTC takes an external battery.2,1
Diagnostics
- The green LED blinks error codes, e.g. 7 short blinks = kernel not found. Newer models show a diagnostic screen over HDMI during boot.2
- Update the system with
sudo apt update && sudo apt full-upgrade, the bootloader withrpi-eeprom-update.2
What this means
- Smart-home server: Synthesis: the RPi 5 is much faster (Cortex-A76 vs. A72) and, above all, supports NVMe via PCIe. For databases and multiple containers, NVMe is more reliable and faster than microSD.
- umbrelOS officially supports the Raspberry Pi 5 booting from NVMe or USB, not microSD.3 It boots from microSD too, but card wear makes it not worth it; see Boot and storage. For x86 it lists a minimum of 4 GB RAM and recommends 8 GB or more.3
- PoE: both models need a separate HAT (PoE+ on the RPi 5).1 Network Zigbee coordinators such as the SLZB-06M or SLZB-MR3 have PoE built in.
Related
Sources
- Raspberry Pi 4 Model B and Raspberry Pi 5 (Raspberry Pi product pages) ↗ — official specifications of the Raspberry Pi 4 Model B and Raspberry Pi 5.
- Raspberry Pi Documentation: Raspberry Pi hardware ↗ — official documentation: boot, bootloader, power, cooling, diagnostics.
- umbrelOS / Umbrel Home (README, app store, product page) ↗ — umbrelOS on the Raspberry Pi 5 and RAM requirements.