Arista Networks CAB-D-D-400G-0.5 Compatible 400G QSFP-DD 8 x 50G PAM4 Passive Copper Twinax Cable, 0.5m (2ft)
This page gives procurement and network teams a precise reference for Arista Networks CAB-D-D-400G-0.5: a 400G DAC assembly in a fixed 0.5m (2ft) configuration. The QSFP-DD to QSFP-DD interface, HT ordering identity and verified specifications are presented together so the required cable can be matched to the bill of materials without confusing it with another length.
OEM Part Number: CAB-D-D-400G-0.5HT Part Number: CAB-D-D-400G-0.5
Product Highlights
- Compatible alternative to Arista Networks CAB-D-D-400G-0.5
- 400G connectivity at 400Gbps
- Interface configuration: QSFP-DD to QSFP-DD
- Fixed length and part number: 0.5m (2ft), CAB-D-D-400G-0.5
- Cable construction: Passive Twinax
- Conductor specification: 30AWG
- Maximum power consumption: 0.1W Per End
- Minimum bend radius: 33mm
Specifications
| HT Part Number | CAB-D-D-400G-0.5 |
|---|---|
| Arista Networks Compatible | CAB-D-D-400G-0.5 |
| Manufacturer | HT |
| Form Factor | QSFP-DD to QSFP-DD |
| Max. Data Rate | 400Gbps |
| Media | Copper |
| Cable Type | Passive Twinax |
| Cable Length | 0.5m (2ft) |
| Wire AWG | 30AWG |
| Minimum Bend Radius | 33mm |
| Max. Power Consumption | 0.1W Per End |
| Jacket Material | PET |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Modulation Format | 8x 50Gbps PAM4 |
| Application | 400G Ethernet |
| Protocols | IEEE 802.3cd, QSFP-DD MSA, CMIS 4.0 |
Signal and Lane Configuration
The listed modulation format is 8x 50Gbps PAM4. Both host interfaces must be configured for the same aggregate rate and lane arrangement. A connector that fits mechanically does not by itself guarantee that the remote port supports this encoding or breakout mode.
Position Within the Length Range
CAB-D-D-400G-0.5 is the shortest of 6 verified length options in this family. It is the preferred choice when the port positions are close and cable slack must be kept to a minimum. The next option is CAB-D-D-400G-1M at 1m (3ft), adding 0.5m for a less direct routing path; selecting it unnecessarily would leave more cable to dress.
Procurement and Port-Mapping Review
A useful purchase order should identify the host platform, the expected OEM code and the exact cable length as separate pieces of information. This prevents a physically similar assembly from being substituted when the port identification or reach is different. For mixed-length installations, prepare one order line per part number and reconcile each delivered cable with its intended pair of ports. For this assembly, the listed conductor specification is 30AWG; the minimum bend radius is 33mm; the stated power consumption is 0.1W Per End; the jacket material is PET.
Power and Thermal Planning
The rated power consumption is 0.1W Per End. Include this load in the host-port power and thermal budget, especially in densely populated switches. Maintain front-panel clearance and do not bundle the cable so tightly that it obstructs airflow around the connectors.
Cable Construction and Routing
This assembly uses 30AWG conductors, PET jacket, minimum bend radius 33mm. These mechanical characteristics affect how the cable should be dressed behind the equipment. Avoid sharp edges, excessive ties and repeated tight bends close to the connector boots.
Network and Protocol Considerations
The intended application is 400G Ethernet. Listed interface and protocol references include IEEE 802.3cd, QSFP-DD MSA, CMIS 4.0. Confirm that the host firmware and port configuration support the same operating mode.
Passive Copper Operation
A passive DAC has no separate optical conversion stage. Its low-power, low-latency operation is useful for short equipment links, but the assembly must remain within the length and signaling mode accepted by both hosts.
Length Selection and Installation Planning
The 0.5m (2ft) length is suited to closely aligned ports where excessive slack would obstruct airflow or complicate dressing. Measure the actual port-to-port path before choosing CAB-D-D-400G-0.5; even a short assembly must retain the specified bend radius and should never be pulled tight behind the equipment.
Arista Networks Compatibility and Factory Testing
Our procurement-oriented compatibility check begins with the OEM reference and ends with a live host link. We record the physical length separately from the identification configuration, so the cable supplied for this page remains the stated version rather than a generic length substitute. Where supported by the host, link stability and diagnostic indications are reviewed together with the established link.
Ordering Information
For a clear bill of materials, quote the OEM reference, HT part number, length and quantity on the same line. Add the switch or server model and software release when a pre-order review is required; project labels can repeat those details for receiving and installation teams. Quantity and any labeling instructions should be attached specifically to CAB-D-D-400G-0.5.
Quality Assurance and Packaging
Before packing, the assembly is checked for connector condition, identification and link operation. Cables for multi-line orders can be labelled and grouped by part number, making it easier to match each length to the procurement record without opening every protective bag. Neutral packaging and customer-specific packing documentation are available on request.
Frequently Asked Questions
Is this an original Arista Networks cable?
No. It is an HT-manufactured compatible alternative for equipment that specifies Arista Networks CAB-D-D-400G-0.5.
Are separate transceivers or patch leads required?
No. This is one complete direct-attach assembly. The ends are not detachable modules and should not be separated from the cable.
Can excess cable be folded into a compact bundle?
No. Use a supported, bend-safe service loop and observe the listed minimum bend radius. Do not crease the cable or tighten ties around the connector boots.
Will any matching connector operate at the same speed?
Not necessarily. Both hosts must support the stated rate, identification, lane mapping and any required breakout configuration; mechanical compatibility alone is insufficient.
Shipping and Lead Time
Standard configurations normally ship within one to three working days, while production quantities are confirmed with the order. Delivery can be arranged by courier, air freight or sea freight, and goods may instead be handed to an appointed forwarder or shipped on the customer’s courier account.