More than 5,000 copper cables, grouped in cartridges at the rear of the rack, link every compute tray to every switch tray without converting signals to light.
What is the copper spine?
In GB200 and GB300 NVL72, four NVLink cartridges mounted vertically at the rear of the rack hold over 5,000 copper cables that join the compute trays to the nine NVLink switch trays, each carrying two NVSwitch chips, for 130 TB/s of all-to-all bandwidth (NVIDIA, Oct 2024). Because the runs stay inside one rack, copper needs no lasers or module power; at 200 Gb/s per lane, IEEE’s objective for copper twinax is a reach of at least 1 m. NVIDIA’s post calls the cables active copper cables, while most descriptions treat them as passive twinax, so stock3d relies on neither adjective. Trays dock blind into the spine through backplane connectors at the rear.
Who makes the cartridges and connectors?
NVIDIA names no cartridge supplier. Luxshare says its Intrepid Cable Cartridge cable-backplane and its 224G Intrepid NEXUS backplane connector are in commercial use in certain mainstream AI clusters, without naming a customer or platform. SemiAnalysis reported in July 2024 that Amphenol’s Paladin backplane was the initial primary source for the NVLink backplane; neither company confirms it, so it is context, and Amphenol is connected on its own AI interconnect disclosure. TE Connectivity markets AdrenaLINE Slingshot cabled-backplane and Catapult near-chip connectors with its own 224G cable. NVIDIA’s Blackwell partner list names Amphenol, TE Connectivity, Luxshare, BizLink and the private Molex without stating their parts.
Where do active electrical cables fit?
An active electrical cable puts signal chips in its plugs so copper can reach farther, mostly between network cards and switches rather than in the spine. Credo’s ZeroFlap AECs integrate retimers, gearboxes and FEC circuitry in the connectors, run up to 7 m and use up to 50% less power than active optical cables. Marvell’s 1.6T AEC DSP named Amphenol, Molex and TE as cable partners (June 2024); Astera Labs sells smart cable modules, BizLink and Luxshare sell active copper cables, and Microchip sells an 800G AEC retimer. Semtech’s CopperEdge redrivers power linear active copper cables such as Amphenol’s 1.6T OSFP cable at under 2 W per cable end. No source ties a specific cable to NVL72.
How to research a copper interconnect company
- Separate the layers: passive cable assembly, backplane connector, the chip inside an active cable and the finished cable brand. One company rarely does all four.
- Treat analyst attributions as context: SemiAnalysis’s Amphenol call is not a disclosure by Amphenol or NVIDIA and sets no evidence level.
- Read company wording closely: “commercial use in certain mainstream AI clusters” names no platform, customer or share.
- Check concentration and exposure: Credo’s ten largest customers were about 90% of fiscal 2026 revenue, while digital data networks were about 13% of TE’s fiscal 2025 sales.
- Follow design changes: a later rack generation can change the spine, the connector or the cable count, so re-check each generation.
- Use the list as a starting point: it is curated, not exhaustive, and the model is illustrative, not a bill of materials.
Sources
- NVIDIA: GB200 NVL72 designs contributed to OCP, Oct 15, 2024
Four NVLink cartridges at the rear hold over 5,000 copper cables for 130 TB/s of all-to-all bandwidth; the Blackwell partner list names Amphenol, BizLink, Luxshare, Molex and TE Connectivity without parts.
- NVIDIA: DGX GB rack systems hardware
Nine 1U NVLink switch trays with two 72-port NVSwitch chips each.
- IEEE P802.3dj: adopted objectives
At 200 Gb/s per lane, a reach of at least 1.0 m over copper twin-axial cable.
- Luxshare-ICT: from interconnect to power and thermal management, Apr 24, 2026
The Intrepid Cable Cartridge and 224G Intrepid NEXUS connector are in commercial use in certain mainstream AI clusters; no customer is named.
- Amphenol: Form 10-K for 2025
An interconnect provider to makers and operators of AI-enabling systems; IT datacom about 36% of 2025 sales.
- TE Connectivity: AdrenaLINE 224G portfolio
Catapult near-chip, Slingshot cabled-backplane and Fastlane cabled-I/O connectors with in-house 224G cable for AI systems.
- Credo: ZeroFlap active electrical cables
Retimers, gearboxes and FEC circuitry in the connectors; up to 7 m; up to 50% less power than active optical cables.
- Credo: Form 10-K for fiscal 2026
ZeroFlap AECs, DSPs and retimers; its ten largest customers were about 90% of fiscal 2026 revenue.
- Marvell: 1.6T PAM4 DSP for active electrical cables, June 27, 2024
Amphenol, Molex and TE Connectivity quoted as cable partners for the 1.6T AEC DSP.
- Semtech: Amphenol and Semtech 1.6T active copper cable, Apr 1, 2025
A 1.6T OSFP linear active copper cable built by Amphenol with Semtech CopperEdge redrivers.
- Semtech: CopperEdge for 800G and 1.6T, Apr 2, 2025
Linear redrivers for active copper cables in AI data centers at under 2 W per cable end.
- Microchip: 800G active electrical cable solution, Nov 8, 2023
The META-DX2C 800G AEC retimer and reference design for generative-AI networks; no cable maker named.
Engineering reference: Cables, optics and connectors example. Company-specific evidence is linked from the profiles below.
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