What Is NVLink Switch?_
An NVLink Switch is a standalone switch appliance built on NVSwitch silicon that extends NVIDIA's NVLink fabric beyond a single rack, joining GPUs across multiple racks into one high-bandwidth NVLink domain. Where NVSwitch chips inside an NVL72 rack handle all-to-all connectivity internally, NVLink Switch appliances connect racks together with external optical cabling that must be routed precisely.
Technical Details
Inside an NVL72 rack, NVSwitch silicon provides every GPU a direct path to every other GPU without external NVLink cables. To build NVLink domains larger than a single rack, NVLink Switch appliances aggregate NVLink ports and connect to the in-rack NVSwitch layer over external links, typically optical. This multi-rack NVLink fabric delivers far higher bandwidth than a conventional InfiniBand or Ethernet back-end network, but it depends on dense, precisely routed optical cabling between racks, where mislabeling or a bad connector degrades the fabric. NVLink Switch is separate from the back-end scale-out network (InfiniBand or Spectrum-X Ethernet), which still connects NVLink domains to each other and to storage. Cable management, polarity, and end-face cleanliness are as critical here as anywhere in the cluster.
How Leviathan Systems Works with NVLink Switch
Leviathan Systems routes and verifies the external optical cabling for multi-rack NVLink Switch fabrics, applying the same labeling, polarity, and end-face inspection discipline used across the cluster.
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