NVIDIA LinkX InifiniBand DAC Cables

Explore direct-attach copper (DAC) cables and splitters for GPU-accelerated computing

NVIDIA^® Mellanox^® LinkX^® InfiniBand DAC cables are the lowest-cost way to create high-speed, low-latency 100G/EDR and 200G/HDR and 400G/NDR links in InfiniBand switching networks and for NVIDIA GPU-accelerated artificial intelligence end-to-end systems. InfiniBand is all about high bandwidth and low latency interconnects. Designed and manufactured by LinkX, every part is extensively tested in live GPU and switching systems and used in NVIDIA-Certified Systems™.

New Splitters and Active Copper Cables

Passive DACs use simply copper wires and have no electronics, consume zero power, and have the lowest latency and insertion loss. New active DACs, aka active copper cables (ACC), include signal-boosting integrated circuits (ICs) in the cable end to extend the reach up to 4 meters at 200G HDR. Also, with HDR is the new 2x splitter that splits a 200G HDR (4x 50G-PAM4) into two ends of 100G HDR100 (2x 50G-PAM4), enabling a 40-port QM8700 InfiniBand switch to support 80 ports of 100G HDR100.

LinkX DAC cables are designed for use in supercomputers and hyperscale systems that have the most stringent requirements and the lowest bit error
ratio (BER).

Highlights

PORT SPEEDS*

FDR, EDR, HDR, NDR

STRAIGHT AND SPLITTERS

1x, 2x, 4x

FORM FACTORS**

QSFP28, QSFP56, OSFP

MODULATION TYPES***

25G NRZ, 50G-PAM4, 100G-PAM4

* FDR: fourteen data rate (4x14G-NRZ), EDR: Extended Data Rate (4x25G-NRZ), HDR: High Data Rate (4x50G-PAM4), NDR: Next Data Rate (4x100G-PAM4)
** QSFP: quad small form-factor pluggable; OSFP: octal small form factor pluggable
*** NRZ: non-return-to-zero; 50G-PAM4: 50G-4-level pulse amplitude modulation, 100G-PAM4

Ultimate Low-Latency, Low-Power Interconnects

InfiniBand systems are designed end to end for the lowest-latency signaling possible for GPU accelerated artificial intelligence systems. Containing no electronics, DACs offer the lowest latency, so are widely used in data centers to connect servers and GPU compute systems to the top-of-rack (TOR) switches and link spine-to-super-spine switches inside racks over short cable lengths. DACs are also used to create InfiniBand storage fabrics with hard-disk-drive (HDD) and flash memory subsystems.

Key Features

HDR passive DACs for up to 2 meters; AOCs for 3 and 4 meters
Available at lengths from .5 meter to 3, 5, and 7 meters, depending on the line rate in QSFP+, QSFP28, and QSFP56 and OSFP form factors
Extensively tested for low bit error ratings, yielding substantially better results than InfiniBand Trade Association (IBTA) standards and most competitors
Available in 25G-NRZ and 50G-PAM4 modulation

Benefits

Lowest-cost, lowest-latency, high-speed interconnect
Passive DACs consumes zero power and low insertion losses
Every part tested in NVIDIA GPU and switching systems for guaranteed out-of-the-box optimal operation
Tested and certified in NVIDIA GPU, DGX™, EGX™, and DPU systems
400Gb/s NDR (4x100G-PAM4) DACs and ACCs coming in 2021

NVIDIA DGX A100

InfiniBand is the protocol of choice for creating high bandwidth, low-latency networks linking NVIDIA GPU-based systems to other DGX and DPU systems. The DGX A100 supports eight 200Gb/s HDR host channel adapters (HCAs) linking to other DGX systems via Quantum network switches. Two 200Gb/s HDR InfiniBand or Ethernet interface cards link to storage HDD, SSDs and flash memory subsystems.

InfiniBand transceivers extend networks inside a cluster where the transceiver and fibers need to be disconnected from each other and outside the cluster linking to other clusters and infrastructures. Multi-mode transceivers for short reaches <100m and single-mode transceivers for up to 500m, 2km and 10km in large link budgets.

InfiniBand DAC Cables

Splitter cables are also called “breakout” cables.
* PVC: polyvinyl chloride jacket; LSZH: low-smoke, zero-halogen cables.
** Check product briefs for detailed product codes and specifications.