Hardware Documentation: Xerxes Pi
A high-density server motherboard in a 120 mm × 40 mm form factor designed for a 1U mini or full sized rack space and compatible with the Raspberry Pi Compute Module tailored for microserver or cluster use.
Core Compatibility
| Feature | Details |
|---|---|
| Compute Modules | Raspberry Pi® CM4 and CM5, Radxa® CM5, OrangePi CM5, and other Compute Module compatible boards. (See A) |
| M.2 | The M.2 connector follows the PCIe specifications documented by Raspberry Pi in their CM5 datasheet. (See H) Please note: Rev A Xerxes Pi M.2 is only compatible with Raspberry Pi CM5 compute modules. |
| Ethernet | On-board Gigabit Ethernet PHY using the Broadcom BCM54210PE which is IEEE 1588-2008 compliant with MDI crossover, pair skew and pair polarity correction. (See G) |
| Fan Connector | Standard header pin fan connector. (See B) |
| USB | Power connector is USB-C 2.0 OTG (See E) |
| Fan | Standard CM5 fan SH connector (See B) |
| I2C | Qwiic compatible SH connector for I2C (See C) |
| Debugger | JTAG compatible UART debug SH connector (See F) |
| Power Jumper | Jumper between POE and USB power via safety jumper switch (See J) |
| POE | Power over Ethernet header pins connect to an optional daughterboard seen in this diagram. (See D) |
| Boot | Boot Jumper (See K) |
| SD | SD Card for compute modules without eMMC (See I) |
| Model Viewer |  |
Form Factor & Physical
| Feature | Details |
|---|---|
| Dimensions | 120 mm × 40 mm |
| Standard | Fractional Nano ITX |
| Mounting | Aligned for 1U chassis density; side-to-side airflow |
| Stackable Array-ready | Designed to slot into a blade or sled within a dense server chassis. Please see further down for a video describing the process for stacking a mini rack |
| Size compared to a Mobile Phone |  |
Connectivity
| Feature | Details |
|---|---|
| Networking | 1× Gigabit Ethernet RJ45 |
| USB | 1 USB 2.0 port for power and data |
| PCIe | 1× PCIe Gen 2 x1 via onboard M.2 M-key slot (Compatible only with Raspberry Pi CM5) |
| Display | via optional M.2 Oculink® board to optional PCIe Graphics board, including latest generation AMD GPU graphics cards |
Storage Options
| Feature | Details |
|---|---|
| Onboard eMMC | (from compute module) |
| M.2 slot | Key M for NVMe or SATA SSD (Compatible only with Raspberry Pi CM5) |
| microSD card slot | Only for CM4 or CM5 Lite versions. microSD care is reserved for compute module cards which do not contrain storage memory |
| NVME and microSD |  |
Power
| Feature | Details |
|---|---|
| Input Voltage | 5V DC via USB-C OTG connector |
| Power Efficiency | Optimized low-power draw (~5–8W per module under load) power draw may vary depending on the M.2 care used |
Cluster Integration Features
| Feature | Details |
|---|---|
| I2C Qwiic Connector | For Qwiic compatible accessories |
| UART Debug SH Connector | For direct terminal debugging |
| POE connector | Compatibility for integrated POE daughterboard |
| LED indicators | Power, Activity, Network status |
| Rack Enclosures | Available in 19" and mini-rack sizes, open source and pre-printed with links to sliced models up soon for download here |
| Model Description Video |  |
Use Case
Ideal for:
- Raspberry Pi clusters
- Edge computing nodes
- Kubernetes micro-clouds
- Home lab compute bricks in custom 1U enclosures