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1m (3ft) NVIDIA (InfiniBand) QDD-400-CU1M Compatible 400G QSFP-DD Passive Direct Attach Copper Twinax Cable
P/N: QDD-400G-CU
US$119.00
10
Reviews
5
Questions
safeguard
4-Year Warranty
30-Day Returns
30-Day Exchange
(1000 In Stock)

Product Highlights

Near-Zero Power, Low Latency and Insertion Loss
Tested in Targeted Switches for Superior Performance, Quality, and Reliability
Highly Reliable with No Electronics or Optical Connectors
Designed to Beyond IEEE Industry BER Standards for Reliable Operation Under Harsh Operating Conditions
Simplifies Patching and Offers a Cost-effective Way for Short Links
Compliant to QSFP-DD MSA, CMIS Rev4.0, OIF 56G PAM4
Minimum Bend Radius 33.5mm for Flexible Routing
8x50G PAM4 400GAUI-8 Electrical Interface
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1m (3ft) NVIDIA (InfiniBand) QDD-400-CU1M Compatible 400G QSFP-DD Passive Direct Attach Copper Twinax Cable
The NVIDIA (InfiniBand) 400G QSFP-DD DAC provides a QSFP-DD-to-QSFP-DD copper direct-attach solution and it is suitable for very short links and offer a cost-effective way to establish a 400-Gigabit link between QSFP-400G ports of switches/routers within racks and across adjacent racks. This DAC is designed with ultra-low loss materials, square rings, twisted pair cable 8 wires and shell extension construction for superior mechanical properties and bending performance. It is tested in actual switching systems to ensure optimal signal integrity and the best end-to-end performance. FS currently offers 400G QSFP-DD DAC in lengths of 0.5, 1, 1.5, 2, 2.5, and 3 meters, ideal for SDN, ML, and Cloud Computing.
Specifications
Part Number
QDD-400-CU
Vendor Name
AICPLIGHT
Form Factor
QSFP-DD to QSFP-DD
Max Data Rate
400Gbps
Media
Copper
Cable Type
Passive Twinax
Cable Length
1m (3ft)
Wire AWG
30AWG
Minimum Bend Radius
33.5mm
Power Consumption
≤0.1W
Jacket Material
PVC (OFNR)
Temperature
0 to 70°C (32 to 158°F)
Modulation Format
8x 50Gb/s PAM4
Application
400G Ethernet
Protocols
IEEE 802.3cd, QSFP-DD MSA, CMIS 4.0
Warranty
5 Years
Certification
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Questions & Answers
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All (5) Management (1)Product (1)Compatibility (1)Installation (1)Performance (1)
Q:

Do these cables require special configuration after plugging in?

by e***m on 2025-07-10 09:45:21

A:

No special configuration is needed. The cables are hot-swappable and designed for plug-and-play operation in InfiniBand environments.

by CPLIGHT on 2025-07-10 10:25:43

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Q:

Can these cables be used for GPU Direct RDMA communication?

by t***m on 2025-07-10 09:29:59

A:

Absolutely. These InfiniBand cables support GPU Direct RDMA, enabling low-latency, high-throughput data transfers directly between GPUs across the fabric.

by CPLIGHT on 2025-07-10 10:24:35

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Q:

Do InfiniBand AOC cables support long-distance connections?

by f***m on 2025-07-10 09:22:14

A:

Yes, AOC (Active Optical Cables) support longer distances than DACs, typically up to 30 meters or more, while maintaining low latency and high bandwidth transmission.

by CPLIGHT on 2025-07-10 10:26:18

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Q:

What is the difference between HDR and NDR InfiniBand cables?

by m***m on 2025-07-10 09:08:01

A:

HDR (High Data Rate) supports up to 200Gb/s per port, while NDR (Next Data Rate) can handle 400Gb/s. Both are used for high-performance computing, but NDR is designed for newer-generation systems requiring ultra-high bandwidth.

by Helpful on 2025-07-10 10:23:26

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Q:

Are these InfiniBand DAC/AOC cables compatible with NVIDIA/Mellanox ConnectX NICs?

by u***m on 2025-07-10 09:05:06

A:

Yes, our InfiniBand DAC and AOC cables are fully compatible with NVIDIA/Mellanox ConnectX-5, ConnectX-6, and ConnectX-7 NICs, as well as with NVIDIA Quantum and Spectrum switches.

by CPLIGHT on 2025-07-10 10:24:04

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Customer Reviews
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All (10) Performance (1)Compatibility (1)Ease of Use (1)Customer Support (1)Value (1)Reliability (1)Flexibility (1)Scalability (1)Quality (1)Delivery (1)
7
7***m
2025-05-31 20:32:16
Confirmed Purchase
5.0

We used breakout versions (1x400G to 4x100G) to expand our interconnect fabric and they worked flawlessly.

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7
7***m
2025-05-27 21:04:36
Confirmed Purchase
5.0

The connectors are solid, and the shielding is robust. No damage or signal degradation even after multiple insertions.

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6
6***m
2025-05-17 20:42:29
Confirmed Purchase
5.0

Cables were clearly labeled and well packaged. Plug-and-play setup made our data center upgrade smooth and fast.

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Q
Q***m
2025-05-14 07:39:05
Confirmed Purchase
5.0

Customer service helped confirm the pinout for a custom breakout setup. Very knowledgeable and responsive team.

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H
H***m
2025-05-12 23:40:35
Confirmed Purchase
5.0

Order arrived earlier than expected. All cables were individually tested and labeled, saving us time during rack installation.

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e
e***m
2025-05-09 14:02:16
Confirmed Purchase
5.0

Compared to OEM versions, these cables offer the same performance at a significantly lower cost. Great for large-scale deployment.

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1
1***m
2025-05-03 11:13:04
Confirmed Purchase
5.0

We used these InfiniBand HDR DAC cables to link GPU servers in our HPC cluster. The latency and bandwidth were excellent — no packet loss even under full load.

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Q
Q***m
2025-05-01 11:22:18
Confirmed Purchase
5.0

Worked out of the box with ConnectX-6 NICs and Quantum switches. Auto-negotiation and link detection were flawless across all ports.

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O
O***m
2025-04-29 18:32:23
Confirmed Purchase
5.0

We had tight routing paths between racks and these DACs were flexible enough for clean cable management without strain.

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B
B***m
2025-04-17 20:49:48
Confirmed Purchase
5.0

Running 24/7 in an AI training environment with zero errors so far. Excellent quality and heat management.

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