NJAAKK-N911 QSFP112 400G-Rated Passive DAC Cable, 0.5m – Stacking Cable for NVIDIA DGX Spark, ASUS Ascent GX10, Dell Pro Max GB10 (NJAAKK-0006 Equivalent)

Resilient Tec compatible cable — equivalent to the cables NVIDIA lists as approved for DGX Spark

→ DGX Spark interconnect reference — approved part numbers, real-world throughput, and what to buy at two, three and four or more nodes.

Part Number: NJAAKK-N911
Equivalent to: Amphenol NJAAKK-0006 (0.5 m) — see the part number decoder below
Description: QSFP112 Passive Direct Attach Copper (DAC) cable, 400G-rated, 0.5 m (1.6 ft)

This is a 0.5 m passive direct-attach copper cable with QSFP112 connectors on both ends, rated for up to 400G on hardware that supports it. It is a compatible build supplied by Resilient Tec, matching the specification of the Amphenol NJAAKK-0006 that NVIDIA lists as an approved DGX Spark cable.

On the NVIDIA DGX Spark — and on the OEM GB10 systems built on the same reference platform (HP ZGX Nano AI Station, Dell Pro Max with GB10, ASUS Ascent GX10) — you plug this cable into the system's ConnectX-7 QSFP ports to link two units directly, with no switch required. Per NVIDIA's DGX Spark documentation, each of these QSFP ports operates at up to 200 Gb/s, so the link runs at 200 Gb/s even though the cable itself is QSFP112 / 400G-rated. There is no separate "dedicated stacking port" — the ConnectX-7 QSFP ports are used both for connecting units together and for standard Ethernet / RoCE networking.

Several part numbers circulate for the DGX Spark stacking cable. They are one specification across two manufacturers and two lengths — and length is the only thing that actually separates them:

Looking for the NJAAKK-0006? This is the cable you want — same 0.5 m length, same QSFP112 connectors on both ends, same passive copper construction.

A note on length. Amphenol's own NJAAKK-N911 is the 400 mm version, while compatible suppliers commonly apply the N911 family number to a 0.5 m cable. That is why two listings can both say NJAAKK-N911 and arrive at different lengths. Buy on the stated length, not on the part number alone. This one is 0.5 m.

Each DGX Spark (and each OEM GB10 system) has two ConnectX-7 QSFP ports on the rear panel. These same ports are used both to connect units together and for general Ethernet / RoCE networking. NVIDIA caps each port at up to 200 Gb/s, and notes that using a higher-speed cable does not increase the link rate because the port itself is the limit.

NVIDIA names these approved cables for this connection:

• NJAAKK-N911 (Amphenol, 400 mm) and NJAAKK-0006 (Amphenol, 0.5 m)
• LMTQF022-SD-R (Luxshare, 400 mm) — also listed here

The MCP1650-V00AE30 (200G QSFP56 DAC) is not a part NVIDIA names, but it is a viable, tried-and-tested lower-cost 200G option that our customers have used successfully to stack these systems, with no reported issues.

• Up to four units connect without a switch. Two Sparks take one cable. Three take three cables in a ring, using both QSFP ports on every unit — the configuration NVIDIA documents. Four can also run switchless as a ring of four cables using a custom NCCL build; owners are running it today, but it is outside NVIDIA support and cannot grow past four. A switch is the supported route at four nodes and the only route beyond. How the four-node switchless ring works
• Connects units directly — no switch, transceivers, or adapters required
• 0.5 m is ideal for two compact desktop units placed side by side; NVIDIA references short passive DAC lengths for this use
• Works across the GB10 ecosystem (NVIDIA DGX Spark, HP ZGX Nano AI Station, Dell Pro Max with GB10, ASUS Ascent GX10), which share the same ConnectX-7 networking
• The ConnectX-7 QSFP ports operate in Ethernet mode (with RoCE), not InfiniBand
• Passive copper — no transceivers, no power draw, no firmware

You have two, three or four GB10-based systems (NVIDIA DGX Spark or an HP / Dell / ASUS equivalent) — four as a switchless ring needs a custom NCCL build. You want to link them directly through their ConnectX-7 QSFP ports. You need a 0.5 m passive copper cable with QSFP112 connectors on both ends. You are shopping for an NJAAKK-0006, NJAAKK-N911, NJAAKKR-0006 or LMTQF022-SD-R and want a spec-matching cable at a working price.

NVIDIA DGX Spark Stacking Cable NJAAKK-N911: What It Does, Who Needs It, and How It Compares to the DAC

NJAAKK-N911 vs NJAAKK-0006 vs LMTQF022-SD-R: What's the Difference?

How to Connect Two NVIDIA DGX Spark Systems: The Cable You Need and Why

Can You Build a 4-Node DGX Spark Cluster Without a Switch? The Ring That Works and the Breakout Trick That Doesn't

COMPATIBILITY DOCUMENTATION

Download compatibility report: NJAAKK-N911_Compatibility_Report

Guide includes: compatibility notes for NVIDIA DGX Spark and OEM GB10 platforms, ConnectX-7 200GbE port verification, dual-system interconnect setup instructions.