10/100BASE-T SFPArista Networks QDD-400G-2QPC Compatible 400G QSFP-DD 8 x 50G PAM4 to 2 x 200G QSFP56 4 x 50G PAM4 Passive Copper Breakout Cable
A 400G direct-attached link depends on the correct host identity, interface mode and physical length. This page covers the Arista Networks QDD-400G-2QPC compatible DAC series in direct-attach, including 1m (3ft) and 2m (7ft). Each documented length-specific OEM reference is linked separately where an individual product page is available.
Series Part Number: QDD-400G-2QPCHT Part Number: QDD-400G-2QPC
Product Highlights
- HT-manufactured compatible alternative for Arista Networks QDD-400G-2QPC
- 400G aggregate connectivity at 400Gbps
- Passive Twinax / Copper
- Length configurations covered: 1m (3ft) and 2m (7ft)
- Conductor specification: 30AWG
- Power consumption: 0.1W (QSFP-DD End) 0.1W (QSFP56 Per End)
- Operating temperature: 0 to 70°C (32 to 158°F)
Available Lengths and Corresponding Part Numbers
The documented series configuration is 1m (3ft) and 2m (7ft). Use the relevant OEM reference below together with the HT identity and required length when requesting a quotation. If another length carries a different OEM part number, it must be reviewed and ordered as that distinct configuration.
Compatible OEM Part Numbers
- QDD-400G-2QPC01
Specifications
| HT Part Number | QDD-400G-2QPC |
|---|---|
| Manufacturer | HT |
| Connector Type | QSFP-DD to 2x QSFP56 |
| Max Data Rate | 400Gbps |
| Media | Copper |
| Cable Type | Passive Twinax |
| Cable Length Options Covered | 1m (3ft) and 2m (7ft) |
| Wire AWG | 30AWG |
| Minimum Bend Radius | 33.5mm |
| Max. Power Consumption | 0.1W (QSFP-DD End) 0.1W (QSFP56 Per End) |
| Jacket Material | PVC |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Protocols | IEEE802.3Bj, By, IEEE802.3CD, SFF-8679, SFF-8636 |
| Application | 400G Ethernet |
| Modulation Technology | PAM4 |
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 the stated interface and the aggregate rate is 400G. The stated application is 400G Ethernet.
Quality Assurance and Packaging
Each assembly receives a visual connector inspection and functional link check before it is coiled and protected. Packaging is selected to avoid compressing the cable into a tight bundle, and optional rack-based labels help maintain an orderly installation when many identical interfaces are populated together. Both connector ends are inspected as part of the complete assembly, and protective packing is selected to avoid tight bends during transport and storage.
Cable Construction and Routing
For this assembly, the conductor specification is 30AWG; the jacket material is PVC; the minimum bend radius is 33.5mm; the operating temperature is 0 to 70°C (32 to 158°F); the power consumption is 0.1W (QSFP-DD End) 0.1W (QSFP56 Per End). These parameters belong in the installation review rather than being treated as catalogue trivia. Route the cable through its intended managers without tension, avoid pressure close to the connector boots and leave enough space to operate the latches. Any service loop must respect the stated bend limit.
High-Density Rack Integration
In a densely populated rack, connector access and airflow are part of the link design. Choose the shortest length that follows the managed path comfortably, avoid tight bundles around the connector housings and preserve room for latch operation. Where power consumption is listed, include every populated interface in the host thermal budget rather than assessing a single cable in isolation. For this series, keep the interface rate, DAC construction and length-specific OEM reference together throughout that review.
Ordering Information
Provide the exact part number, length, quantity and target interface density. For multi-rack projects, list each length separately and identify any preferred carton grouping. Host model and software information can be included for a compatibility review before production or dispatch. 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 QDD-400G-2QPC identifies the product family; the linked page provides the final length-specific identity.
Arista Networks Compatibility and Factory Testing
The assembly is evaluated for host recognition and stable link operation, with diagnostics checked where the interface provides them. This approach verifies more than electrical or optical continuity. Exact platform and firmware information remains valuable in high-density deployments because port mode and qualification policy can differ within the same connector family. 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.
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.
Frequently Asked Questions
Is this an original Arista Networks cable?
No. It is an HT-manufactured compatible cable for equipment that specifies QDD-400G-2QPC, not an original Arista Networks-branded product.
Are different lengths and OEM part numbers separate products?
Yes. Where a length has its own OEM reference, follow the corresponding link above and order that exact part number on its own line. Do not substitute another length only because the connector arrangement is the same.
Does this DAC cable require separate modules at each end?
No. The connector ends and cable form one complete direct-attach assembly. The ends are not detachable standalone transceivers, and the complete product is tested together.
What information helps confirm compatibility?
Provide the equipment manufacturer and model, port type, hardware revision and software release, together with the required OEM reference, length and quantity. Breakout projects should also identify the intended lane configuration.
