Arista Networks CAB-D-8S-400G Compatible 400G QSFP-DD 8 x 50G PAM4 to 8 x 50G SFP56 50G PAM4 Passive Copper Breakout Cable

Product Highlights

• HT-manufactured compatible alternative for Arista Networks CAB-D-8S-400G
• 400G aggregate connectivity at 400Gbps
• Interface configuration: QSFP-DD to 8x SFP56
• Passive Breakout DAC / Copper
• Length configurations covered: 0.5m (2ft), 1m (3ft), 1.5m (5ft), 2m (7ft), 2.5m (8ft) and 3m (10ft)
• Conductor specification: 28AWG
• Power consumption: 0.1W (QSFP-DD End)0.1W (SFP56 Per End)

Available Lengths and Corresponding Part Numbers

The documented configurations are 0.5m (2ft), 1m (3ft), 1.5m (5ft), 2m (7ft), 2.5m (8ft) and 3m (10ft). Each link below opens the separate product page for that physical length and its corresponding OEM part number. Select the exact assembly required by the route and purchase order; custom project lengths can be discussed separately.

Compatible OEM Part Numbers

• CAB-D-8S-400G-0.5M
• CAB-D-8S-400G-1M
• CAB-D-8S-400G-1.5M
• CAB-D-8S-400G-2M
• CAB-D-8S-400G-2.5M
• CAB-D-8S-400G-3M

Specifications

Applications and Deployment

Passive twinax cables are commonly selected for short switch-to-switch, switch-to-server and accelerator connections within or between nearby racks. With no separate optical conversion stage, they offer a simple low-power physical link. The assembly must nevertheless remain within the length, signaling rate and qualification limits accepted by both hosts. For this series, the listed interface is QSFP-DD to 8x SFP56 and the aggregate rate is 400G.

Arista Networks Compatibility and Factory Testing

The verification process combines digital identification with a live link test and diagnostic observation. Host model, hardware revision and software release are useful inputs because qualification behavior can change between platform generations; those details allow platform-specific requirements to be reviewed before the cable is packed. Series-level inspection is followed by the exact length and OEM configuration selected for dispatch. Functional verification includes link establishment and diagnostic indications where the host exposes them.

Cable Construction and Routing

The specification table records the conductor specification is 28AWG; the jacket material is PVC (OFNR); the minimum bend radius is 39.5mm; the power consumption is 0.1W (QSFP-DD End)0.1W (SFP56 Per End). Use those values when preparing the rack pathway and receiving checklist. Do not pull a connector by its cable, compress the run under tight ties or force excess length into a sharp coil. Connector protection should remain in place until the assembly is ready for insertion.

Interoperability and Configuration Checks

Check three layers before deployment: the host must accept the cable identification, the port must support the stated aggregate rate, and the lane configuration must match the attached interfaces. On breakout hardware, also confirm channelization and the mapping of every branch. These checks are particularly important when similar-looking ports operate at different speeds or under different firmware settings. For this series, keep the interface rate, DAC construction and length-specific OEM reference together throughout that review.

Ordering Information

Specify the OEM part number and fixed length, then provide the intended host configuration if the link uses channelized or breakout ports. Separate part numbers should be used for separate lengths. This gives the compatibility review enough information to check both the physical assembly and the intended operating mode. For this series, follow the corresponding length link, quote that exact OEM part number and keep different lengths on separate order lines. HT part number CAB-D-8S-400G identifies the product family; the linked page provides the final length-specific identity.

Shipping and Lead Time

Standard configurations normally ship within one to three working days, with production lead times confirmed for larger quantities. International courier, air freight and sea freight are available; customer courier accounts and nominated forwarders are accepted.

Quality Assurance and Packaging

Functional inspection covers identification, link establishment and the condition of both connector assemblies. The cable is then protected against dust and connector damage and packed without sharp bends. Labels can include the customer reference and host-platform note when requested for a controlled deployment. Both connector ends are inspected as part of the complete assembly, and protective packing is selected to avoid tight bends during transport and storage.

Frequently Asked Questions