V100 SXM2 pinout and NVLink reference

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Summary

An open-source reference kit for NVIDIA V100 SXM2 pinouts and NVLink interconnects, providing 800 canonical contacts, connection tables, and KiCad starter designs for two- and four-GPU configurations as groundwork for an open carrier board.

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pigeon-labs-stack/v100-sxm2-reference

Source: https://github.com/pigeon-labs-stack/v100-sxm2-reference

V100 SXM2 reference kit

V100 SXM2 pinout and NVLink reference

This project aims to become an open-source carrier-board design for NVIDIA V100 SXM2 modules, including NVLink connections for two- and four-GPU configurations.

While that board is being developed, this reference kit shares the pin mappings, connection plans and connector-only KiCad resources so other people can develop their own designs.

My contribution so far is primarily curation: gathering public information, comparing sources, reconciling connector orientation and signal names, and making the results easier to follow. The original reverse-engineering work belongs to its authors, credited in Sources and attribution.

Getting started

  1. Download the complete reference ZIP from v0.1.0-reference, or use Code > Download ZIP for the current development files.
  2. Extract the archive and keep the directory structure. Choose a single-, two- or four-module KiCad starter, then open its .kicad_pro file in KiCad 10.0.7 or a compatible newer version. Keep the whole kicad/ folder so the shared symbol library is available.
  3. For reading without KiCad, use the complete schematic PDFs or standalone workbook.

The download guide includes print editions and library-path help. Change notes identify reference editions. This is a public reference pre-release, not a hardware-qualified carrier board.

Start with what you need

I want to…Start here
Find a contact on connector A or BPin maps and naming
Plan a connection between two V100sTwo-GPU NVLink guide
Plan a four-V100 interconnectFour-GPU NVLink guide
Use the connector symbols in my own designKiCad starter and previews
Start with two or four V100s already connected by NVLinkChoose a KiCad starter
Work offline with the full referenceDownload the standalone workbook
Browse or print every schematic sheet without KiCadComplete PDF sets
Check what is established and what is openStatus and limitations

What is included

  • 800 canonical contacts: 400 on connector A and 400 on connector B, with signal names, evidence and electrical-treatment notes.
  • Two- and four-GPU connection tables: exact Connector B pads, directions, lanes and polarity.
  • Three editable KiCad starters: one module’s A/B connectors, plus two- and four-module versions with NVLink data connected. Every contact stays labelled, including unconnected clocks, power and control pins. No regulator, power-control or clock circuits are included.
  • Catppuccin Mocha visuals: contact maps, topology diagrams, schematic previews and the standalone dark reference workbook. An optional KiCad colour theme is included.

External clock required: the NVLink starter schematics show data wiring, not a complete working NVLink implementation. Each V100 needs a 156.25 MHz differential NVHS clock on B/E20 (+) and B/F20 (−). The separate PCIe clock is 100 MHz on A/E7 (+) and A/F7 (−). Clock requirements and scope.

Schematics at a glance

These are the actual connector-only KiCad schematics: 400 labelled contacts on A and 400 on B. Click a preview to open the full-size vector drawing. The two- and four-GPU NVLink arrangements are shown separately below and in the connection guides.

Connector A — PCIe, power contacts and control

Connector A KiCad schematic: all 400 labelled contacts

Connector B — NVLink and management

Connector B KiCad schematic: all 400 labelled contacts

Open the KiCad project · Schematic overview · KiCad guide

NVLink connection plans

The full six-group two-GPU arrangement is derived from the documented pairing families; the four-GPU arrangement follows the curated topology. Each guide explains its source evidence and remaining uncertainties. These are logical connection plans, not routed bridge schematics.

Two GPUs

Two-GPU logical NVLink group allocations

Open the two-V100 KiCad project · Native schematic previews

Four GPUs

Four-GPU logical NVLink group allocations

Open the four-V100 KiCad project · Native schematic previews

Two-GPU connections · Four-GPU connections

KiCad footprint preview

Actual dual-connector footprint exported directly by KiCad

The actual local reference footprint, exported directly by KiCad: 800 contact pads, housing outlines and mounting features. A raw PCB footprint is not included in this edition; see footprint availability and open questions and visual provenance.

Connector geometry preview

CAD preview of the two connector arrays

This is a render of an existing project geometry preview, using the Amphenol connector model. It illustrates connector placement; it is not a completed carrier board or proof of connector A/B identity, mating-part selection or viewing direction. See render provenance.

Where this is going

The longer-term goal is a reusable open-source board design. This reference kit currently covers the pin mappings, NVLink connection plans and connector starter. Routed boards, manufacturing outputs and hardware qualification are future work. See the roadmap.

Corrections are particularly useful when they include an oriented drawing, exact source reference, continuity result or measured behaviour. Please distinguish a confirmed observation from an interpretation.

Use the correction and file-help forms, following the contribution guide. To reference this edition in your own work, use GitHub’s Cite this repository option or CITATION.cff, and retain the relevant upstream source credits.

Licence and reuse

Our original hardware design contributions use CERN-OHL-W-2.0; our original documentation, diagrams and workbook presentation use CC BY-SA 4.0. Both allow commercial reuse, with attribution/notices and the applicable reciprocal sharing requirements. See licence scope and full texts and third-party notices. The licences do not claim ownership of pinout facts or replace upstream terms.

Discussion and thanks

Follow the project and join the discussion on the Level1Techs forums: designing an open-source budget 4× V100 SXM2 NVLink backplane.

Thank you to everyone on the Level1Techs forums for your help, ideas and contributions to this project.

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