What Is NVLink Spine?_
The NVLink Spine provides a dedicated, low-latency data path exclusively for GPU-to-GPU traffic, bypassing the host CPU and standard network interfaces. In systems like the NVL72, it forms a high-bandwidth interconnect topology among up to 72 GPUs within one rack. This spine is entirely copper-based, using high-density connectors and cabling to maintain signal integrity over the short distances inside the rack.
Technical Details
The NVLink Spine uses copper conductors, not fiber optics, because the physical span within a single rack is short enough to avoid signal degradation at the required data rates. Each GPU connects to the spine via multiple NVLink links, with the aggregate bandwidth per GPU reaching several hundred GB/s in each direction. The spine's cabling and backplane are designed to be passive, relying on the GPU's integrated NVLink controllers for signal driving and equalization. Physical installation involves routing thick copper cable bundles between GPU trays and the central spine assembly, with careful attention to bend radius and strain relief per OEM specifications.
How Leviathan Systems Works with NVLink Spine
During rack assembly for NVL72 deployments, the installation crew secures the central backplane chassis and routes the copper cable bundles from each GPU tray to the spine's connectors. This step is critical before any liquid cooling or network cabling, as the spine defines the physical layout of the GPU-to-GPU interconnect.
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