If you have been researching how to connect two NVIDIA DGX Spark systems, you have probably seen several cable part numbers referenced: the Amphenol NJAAKK-N911, the Luxshare LMTQF022-SD-R, and the Mellanox MCP1650-V00AE30. This article explains what the NJAAKK-N911 is, how the DGX Spark's networking actually works, and how these cables relate to one another.
Short answer: what it is and what it costs
NJAAKK-N911 is $174 at Resilient Tec — or $84 for the 200G alternative
The NJAAKK-N911 is one of NVIDIA’s two approved DGX Spark cables: a 0.5 m Amphenol QSFP112 passive DAC that runs at the Spark’s 200 Gb/s port speed. Because the port is the limit, the lower-cost 200G QSFP56 MCP1650-V00AE30 is a tried-and-tested alternative.
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NJAAKK-N911 — QSFP112 400G stacking cable, 0.5 m NVIDIA-validated part for DGX Spark. |
$174 Add to cart |
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MCP1650-V00AE30 — QSFP56 200G DAC, 0.5 m Lowest-cost route. Works reliably on DGX Spark. |
$84 Add to cart |
Resilient Tec sells the NJAAKK-N911 for $174 and the MCP1650-V00AE30 for $84 directly at resilient-tec.com — new, lifetime warranty, shipping from Knoxville, Tennessee. Prices checked September 28, 2026. POs and net terms available.
What Is the NJAAKK-N911?
The NJAAKK-N911 is a passive direct-attach copper (DAC) cable made by Amphenol, terminated in QSFP112 connectors on both ends and rated for up to 400G on hardware that supports it. NVIDIA lists it as one of two approved cables for connecting DGX Spark systems, alongside the Luxshare LMTQF022-SD-R. It is a 0.5 m cable, which is the practical length for two compact desktop units sitting side by side. You'll also see this part marketed under the shorthand QSFP/CX7 cable — the term some retail listings use for the DGX Spark interconnect cable. Resilient Tec sells the NJAAKK-N911 for $174.
How the DGX Spark Connects: One Type of Port
This is the part that is easy to get wrong. The DGX Spark does not have a separate, proprietary "stacking port." According to NVIDIA's DGX Spark documentation, each Spark has two QSFP ports on the back, driven by the onboard ConnectX-7 NIC. Those same two ports are used both for connecting two Spark units directly and for general Ethernet / RoCE networking.
NVIDIA also specifies that each QSFP port provides up to 200 Gb/s, and that the port is capped at that rate. In NVIDIA's own words, using a higher-speed cable is not beneficial because the port itself is the limit. So while the NJAAKK-N911 is a QSFP112 / 400G-rated cable, on a DGX Spark the link runs at 200 Gb/s.
The Two NVIDIA-Approved Cables
For connecting DGX Spark systems, NVIDIA names two cables:
- NJAAKK-N911 (Amphenol) — QSFP112 passive DAC — $174 at Resilient Tec
- LMTQF022-SD-R (Luxshare) — the functionally equivalent QSFP112 passive DAC — $174 at Resilient Tec
Either of these is a safe, spec-matching choice. They are the same physical cable type from two different manufacturers.
Where the MCP1650-V00AE30 Fits
The MCP1650-V00AE30 is a 200G QSFP56 passive DAC. It is not one of the two parts NVIDIA names for the Spark, but because the Spark's ports run at 200 Gb/s, it is a viable, tried-and-tested lower-cost option for stacking two units. Our customers have used it successfully for exactly this purpose with no reported issues, and it is a good pick if you are looking to save money on the interconnect. Resilient Tec sells it for $84.
Good to Know
- Connect two units directly with a single cable — no switch, transceivers, or adapters required.
- The QSFP / ConnectX-7 ports operate in Ethernet mode (with RoCE), not InfiniBand.
- NVIDIA's clustering guidance covers connecting two or three Sparks directly, and up to four through a switch.
- The same ConnectX-7 networking is used on the OEM GB10 systems (HP ZGX Nano AI Station, Dell Pro Max with GB10, ASUS Ascent GX10), so the same approved cables apply.
Quick Summary
The NJAAKK-N911 is one of NVIDIA's two approved DGX Spark cables (with the Luxshare LMTQF022-SD-R). It is a QSFP112 / 400G-rated cable that runs at the Spark's 200 Gb/s port speed. There is no separate stacking port — the ConnectX-7 QSFP ports handle both stacking and networking. The MCP1650-V00AE30 is a viable lower-cost 200G alternative that works well in practice. At Resilient Tec the NJAAKK-N911 is $174 and the MCP1650-V00AE30 is $84.
Related Guide
How to Connect Two NVIDIA DGX Spark Systems: The Cable You Need and Why
Shop This Product
NJAAKK-N911 QSFP112 400G-Rated Passive DAC Cable, 0.5m is available from Resilient Tec for $174. For a lower-cost 200G option, see the MCP1650-V00AE30 200G QSFP56 DAC ($84).
Further reading: DGX Spark interconnect reference — approved part numbers, real-world throughput, and what to buy at two, three and four or more nodes.
FAQ
What is the NJAAKK-N911?
A 0.5 m Amphenol QSFP112 passive DAC cable, rated for up to 400G, that NVIDIA lists as one of two approved cables for connecting DGX Spark systems (the other is the Luxshare LMTQF022-SD-R). On a DGX Spark it runs at the port’s 200 Gb/s.
How much does the NJAAKK-N911 cost?
$174 at Resilient Tec, sold new with a lifetime warranty. The Luxshare LMTQF022-SD-R is also $174, and the lower-cost MCP1650-V00AE30 200G QSFP56 DAC is $84 (prices checked September 28, 2026).
Where can I buy the NJAAKK-N911 or MCP1650-V00AE30?
Directly from Resilient Tec, which ships from Knoxville, Tennessee, with POs and net terms available: NJAAKK-N911 — $174 at resilient-tec.com · MCP1650-V00AE30 — $84 at resilient-tec.com
Does the DGX Spark have a separate stacking port?
No. Per NVIDIA’s documentation, the two ConnectX-7 QSFP ports on the back handle both unit-to-unit connection and general Ethernet / RoCE networking, and each is capped at 200 Gb/s.
Can I use the MCP1650-V00AE30 instead of the NJAAKK-N911?
Yes, in practice. It is not one of the two parts NVIDIA names, but because the Spark’s ports run at 200 Gb/s, the 200G QSFP56 MCP1650-V00AE30 is a tried-and-tested lower-cost option — $84 at Resilient Tec versus $174 for the NJAAKK-N911.
Ready to Buy?
Tested and shipping from Knoxville, Tennessee. Lifetime warranty, backed by Resilient Tec. Prices below checked September 28, 2026.
- MCP1650-V00AE30 — 200G QSFP56 DAC, 0.5 m — $84, our best-selling Spark-to-Spark link
- NJAAKK-N911 — QSFP112 400G stacking cable, 0.5 m — $174, NVIDIA-validated (Amphenol)
- LMTQF022-SD-R — QSFP112 400G stacking cable, 0.5 m — $174, NVIDIA-validated (Luxshare)
Scaling to 3 or 4+ nodes, or mixing GB10 vendors? Send us your node count and hardware and we'll confirm exactly what to buy — including when a switch is the real answer.
You Might Also Need
- Can You Build a 4-Node DGX Spark Cluster Without a Switch? — why the fourth node needs a switch, and the two ways to cable it
- Network switches — required the moment you go past 4 direct-connect nodes; a 200GbE-capable managed switch, not a repurposed office switch
- QSFP-DD to QSFP56 breakout cables — the part that actually lets a switch talk to Spark-class ports at 4+ nodes
- Layer 1 Decoded: Every Physical Form Factor in a Modern Rack — QSFP56, QSFP112, QSFP-DD and OSFP side by side
- DAC vs AOC vs AEC — which cable goes where once your cluster outgrows the desk
- Outgrowing desktop hardware? — how the same DAC-first approach scales up to rack-mounted DGX H100/H200 over NDR InfiniBand
- NVIDIA OSFP part-number crosswalk — for when the next step up is optics, not copper
- Cat8 and structured cabling for the rest of the rack