What Is NVLink?_
NVLink is NVIDIA's proprietary high-bandwidth interconnect that enables direct GPU-to-GPU communication without routing through the CPU or PCIe bus. NVLink 5.0 (used in GB200/GB300) provides 1.8 TB/s bidirectional bandwidth per GPU. NVLink connections within an NVL72 rack are internal, but external NVLink Switch configurations require precise cable routing.
Technical Details
NVLink has evolved across multiple generations: NVLink 3.0 (A100, 600 GB/s), NVLink 4.0 (H100/H200, 900 GB/s), and NVLink 5.0 (GB200/GB300, 1.8 TB/s). Within an HGX H100 baseboard, NVLink connects 8 GPUs through NVSwitch. In NVL72 rack systems, NVLink 5.0 creates a unified fabric across all 72 GPUs with 130 TB/s total bandwidth. The NVLink connections within the rack are internal (handled by NVSwitch silicon), meaning deployment teams do not route external NVLink cables for NVL72 systems. However, for multi-rack NVLink domains using NVLink Switch, external optical cables must be precisely routed between racks.
How Leviathan Systems Works with NVLink
Leviathan Systems verifies NVLink interconnect functionality as part of our commissioning process, ensuring all GPU-to-GPU links are operational and performing at specification before handoff.