The SambaRack SN40L-16 is a fully integrated rack system containing compute, networking, and power infrastructure for AI inference workloads. Each rack arrives pre-cabled and ready for datacenter installation—you only need to connect external power and network uplinks.
Do not modify mounting hardware, filler panels, or internal cabling unless directed by SambaNova customer support. Unauthorized changes may affect system operation and cooling. For datacenter power and network connections, refer to the site-survey and installation documents provided by SambaNova.
What’s in the rack
The SambaRack SN40L-16 rack includes a SambaRack SN40L-16 node, networking infrastructure, and power distribution units.
SambaRack SN40L-16 Rack components
This table lists the primary components included at the rack level. These components provide compute capacity, networking, management access, and redundant power for the SambaRack SN40L-16 system.
| Component | Quantity | Description |
|---|
| SambaRack SN40L-16 node | 1 | Accelerator node providing compute resources |
| Juniper QFX5130 Ethernet data switch | 1 | High-bandwidth switch providing user access to inference services |
| Juniper EX-series access (management) switch | 1 | Dedicated network for system and component management |
| Lantronix serial console server | 1 | Provides CLI access to manage all rack components |
| Power Distribution Units (PDUs) | 4 | Provide redundant power for system operation |
SambaRack SN40L-16 Node components
This table details the components that make up a single SambaRack SN40L-16 node. These components deliver accelerator compute capability and support system management and monitoring.
| Component | Quantity | Description |
|---|
| SambaRack SN40L-2 modules (XRDUs) | 8 | Each module contains two Reconfigurable Data Units™ (RDUs), providing a total of 16 RDUs per node. Each XRDU includes a Baseboard Management Controller (BMC) for power control and telemetry. SN40L-2 modules are also referred to as XRDUs, a generation-agnostic term. |
| SambaRack SN40L-H host module | 1 | x86-based server running Red Hat® Enterprise Linux®, used to manage accelerator node operations |
Rack layout
The figure below shows component locations from the rear of the rack. All cabling is performed at the rear.
Component locations (rear view)
| Label | Component | Rack units |
|---|
| 16 | Lantronix serial console server | RU42 |
| 15 | Juniper EX-series management switch | RU41 |
| 14 | Juniper QFX5130 data switch | RU40 |
| 13 | PDU 4 | RU30/RU31 |
| 12 | PDU 3 | RU28/RU29 |
| 11 | PDU 2 | RU26/RU27 |
| 10 | PDU 1 | RU24/RU25 |
| 9 | SN40L-2-XRDU7 | RU21/RU22 |
| 8 | SN40L-2-XRDU6 | RU19/RU20 |
| 7 | SN40L-2-XRDU5 | RU17/RU18 |
| 6 | SN40L-2-XRDU4 | RU15/RU16 |
| 5 | SN40L-H host module | RU13/RU14 |
| 4 | SN40L-2-XRDU3 | RU11/RU12 |
| 3 | SN40L-2-XRDU2 | RU9/RU10 |
| 2 | SN40L-2-XRDU1 | RU7/RU8 |
| 1 | SN40L-2-XRDU0 | RU5/RU6 |
Compute components
SN40L-H host module
The host module manages accelerator operations and provides the primary interface to the rack’s compute resources.
| Port | Description | Connector |
|---|
| 1 | Dual power inlets | C13 to C14 power cord |
| 2 | Net0 1GbE LAN | RJ45, Cat6 |
| 3 | Management LAN (labeled M) | RJ45, Cat6 |
| 4 | Serial connection | Rollover DB9F to RJ45 console cable |
| 5 | Host interface card (HIC) | QSFP-DD |
| 6 | High-bandwidth network ports | QSFP56 |
SN40L-2 XRDU module
Each XRDU module contains two RDUs and connects to both the management network and the high-bandwidth data network.
| Port | Description | Connector |
|---|
| 1 | Host HIC connections | QSFP-DD |
| 2 | Dual power inlets | C19 to C20 power cord |
| 3 | COM serial port | RJ45, Cat6 |
| 4 | Management LAN (MGMT) | RJ45, Cat6 |
| 5 | High-bandwidth network ports | QSFP56 |
Networking components
The rack includes three networking devices: a high-bandwidth data switch for inference traffic, a management switch for component administration, and a serial console server for out-of-band access.
High-bandwidth data switch (Juniper QFX5130)
The QFX5130 provides 400GbE connectivity for all data path components. Connections to XRDUs and the host module use 400GbE to 2×200GbE DAC splitter cables, delivering 200GbE per endpoint.
| Port | Description | Connector |
|---|
| 1 | 400GbE ports (0–31) | QSFP-DD |
| 2 | Management port (em0) | RJ45, Cat6 |
| 3 | Console port (CON) | RJ45, Ethernet serial cable |
| 4 | Dual power inlets | C14 to C15 power cord |
Port assignments
The figures below show port assignments for the SN40L-H and SN40L-2 XRDUs. The table details all high-bandwidth data switch connections using 400GbE to 2×200GbE DAC splitter cables.
High-bandwidth data switch cabling is configured at the factory. Do not modify unless directed by SambaNova support.
| Switch port | Destination | Component port |
|---|
| 0:1 | SN40L-2-XRDU0 | PCIe slot 1 - Port 0 |
| 0:2 | SN40L-2-XRDU1 | PCIe slot 1 - Port 0 |
| 1:1 | SN40L-2-XRDU2 | PCIe slot 1 - Port 0 |
| 1:2 | SN40L-2-XRDU3 | PCIe slot 1 - Port 0 |
| 2:1 | SN40L-2-XRDU4 | PCIe slot 1 - Port 0 |
| 2:2 | SN40L-2-XRDU5 | PCIe slot 1 - Port 0 |
| 3:1 | SN40L-2-XRDU6 | PCIe slot 1 - Port 0 |
| 3:2 | SN40L-2-XRDU7 | PCIe slot 1 - Port 0 |
| 16:1 | SN40L-H | PCIe slot 3 - Port 0 |
| 16:2 | — | — |
| 27–30 | LAG uplinks to Core Services Rack | — |
| 31 | Reserved | — |
Management switch (Juniper EX-series)
The EX-series switch provides a dedicated management network for all rack components. It is mounted at RU41.
The management switch uses a specific configuration. Modifying or factory-resetting the switch may result in a non-functioning system.
Management switch cabling is not user-accessible. The uplink port is exposed via a patch coupler labeled “AccSw MGMT Uplink” in the upper left rear of the rack.
| Port | Description | Connector |
|---|
| 1 | 1GbE ports (0–47) | RJ45, Cat6 |
| 2 | Console port | RJ45, Cat6 |
| 3 | Management port (em0) | RJ45, Cat6 |
| 4 | Dual power inlets | C13 to C14 power cord |
Port assignments
The table below details the management switch connections to all rack components.
Management switch cabling is configured at the factory. Do not modify unless directed by SambaNova support.
| Switch port | Destination | Component port |
|---|
| 0–1 | — | — |
| 2 | Juniper QFX5130 data switch | MGMT |
| 3 | SN40L-2-XRDU0 | MGMT |
| 4 | SN40L-2-XRDU1 | MGMT |
| 5 | SN40L-2-XRDU2 | MGMT |
| 6 | SN40L-2-XRDU3 | MGMT |
| 7–10 | — | — |
| 11 | SN40L-2-XRDU4 | MGMT |
| 12 | SN40L-2-XRDU5 | MGMT |
| 13 | SN40L-2-XRDU6 | MGMT |
| 14 | SN40L-2-XRDU7 | MGMT |
| 15–25 | — | — |
| 26 | PDU 1 | RJ45 labeled 1 |
| 27 | PDU 2 | RJ45 labeled 1 |
| 28 | PDU 3 | RJ45 labeled 1 |
| 29 | PDU 4 | RJ45 labeled 1 |
| 30 | SN40L-H | Port labeled M |
| 31–42 | — | — |
| 43 | SN40L-H | Net0 (left port) |
| 44–46 | — | — |
| 47 | Management network uplink (tagged VLANs) | — |
Serial console server (Lantronix)
The serial console server provides out-of-band CLI access to all rack components for troubleshooting and recovery. It is mounted at RU42.
Serial console server cabling is not user-accessible. The network port is exposed via a patch coupler labeled “SCS NET UPLINK” in the upper left rear of the rack.
| Port | Description | Connector |
|---|
| 1 | Management network (labeled 1) | RJ45, Cat6 or higher |
| 2 | Serial connections (ports 1–32) | RJ45, Ethernet cable |
| 3 | Dual power inlets | C13 to C14 power cord |
Port assignments
The table below details the serial console server connections to all rack components.
Serial console server cabling is configured at the factory. Do not modify unless directed by SambaNova support.
| Server port | Destination | Component port |
|---|
| 1 | Juniper EX-series management switch | CON2 |
| 2 | Juniper QFX5130 data switch | CON |
| 3 | PDU 1 | RJ45 left of USB (labeled 10101) |
| 4 | PDU 2 | RJ45 left of USB (labeled 10101) |
| 5 | PDU 3 | RJ45 left of USB (labeled 10101) |
| 6 | PDU 4 | RJ45 left of USB (labeled 10101) |
| 7–11 | — | — |
| 12 | SN40L-2-XRDU7 | COM |
| 13 | SN40L-2-XRDU6 | COM |
| 14 | — | — |
| 15 | SN40L-2-XRDU5 | COM |
| 16 | SN40L-2-XRDU4 | COM |
| 17–21 | — | — |
| 22 | SN40L-2-XRDU3 | COM |
| 23 | SN40L-2-XRDU2 | COM |
| 24 | SN40L-H | DB9 (PCI card) |
| 25 | SN40L-2-XRDU1 | COM |
| 26 | SN40L-2-XRDU0 | COM |
| 27–32 | — | — |
Power distribution
PDU locations
Four PDUs provide redundant power for all rack components.
| PDU | Rack units |
|---|
| PDU 1 | RU24/RU25 |
| PDU 2 | RU26/RU27 |
| PDU 3 | RU28/RU29 |
| PDU 4 | RU30/RU31 |
Redundancy design
The power architecture protects against multiple failure scenarios:
- Dual power supplies: Each component has two PSUs connected to different PDUs
- Redundant PDU pairs: PDUs 1 and 2 form one pair; PDUs 3 and 4 form another
- Cross-pair distribution: XRDUs 0–3 and the host use PDUs 1/2; XRDUs 4–7 use PDUs 3/4
This design ensures continued operation if any single PSU, PDU, or datacenter power feed fails.
PDU cabling is configured at the factory. Do not modify unless directed by SambaNova support.
To prevent breaker overloads and unexpected outages, use only designated PDU ports. Do not connect anything to unused ports.
Power connections
The following table shows which PDU port powers each component. Each component’s dual PSUs connect to different PDUs within a redundant pair.
Network and management components (PDUs 1 and 2)
| Component | PSU | PDU | Port |
|---|
| Lantronix console server | Left | PDU 1 | 1 |
| Lantronix console server | Right | PDU 2 | 1 |
| Juniper EX-series switch | Left | PDU 1 | 2 |
| Juniper EX-series switch | Right | PDU 2 | 2 |
| Juniper QFX5130 switch | Left | PDU 1 | 13 |
| Juniper QFX5130 switch | Right | PDU 2 | 13 |
Host module (PDUs 1 and 2)
| Component | PSU | PDU | Port |
|---|
| SN40L-H | Left | PDU 1 | 14 |
| SN40L-H | Right | PDU 2 | 14 |
XRDUs 0–3 (PDUs 1 and 2)
| Component | PSU | PDU | Port |
|---|
| SN40L-2-XRDU0 | Top | PDU 1 | 24 |
| SN40L-2-XRDU0 | Bottom | PDU 2 | 24 |
| SN40L-2-XRDU1 | Top | PDU 1 | 22 |
| SN40L-2-XRDU1 | Bottom | PDU 2 | 22 |
| SN40L-2-XRDU2 | Top | PDU 1 | 12 |
| SN40L-2-XRDU2 | Bottom | PDU 2 | 12 |
| SN40L-2-XRDU3 | Top | PDU 1 | 10 |
| SN40L-2-XRDU3 | Bottom | PDU 2 | 10 |
XRDUs 4–7 (PDUs 3 and 4)
| Component | PSU | PDU | Port |
|---|
| SN40L-2-XRDU4 | Top | PDU 3 | 7 |
| SN40L-2-XRDU4 | Bottom | PDU 4 | 7 |
| SN40L-2-XRDU5 | Top | PDU 3 | 19 |
| SN40L-2-XRDU5 | Bottom | PDU 4 | 19 |
| SN40L-2-XRDU6 | Top | PDU 3 | 22 |
| SN40L-2-XRDU6 | Bottom | PDU 4 | 22 |
| SN40L-2-XRDU7 | Top | PDU 3 | 24 |
| SN40L-2-XRDU7 | Bottom | PDU 4 | 24 |
