Appendix A – Terminology

Table 9: Terminology

Term	Definition
Node	The distinct hardware tray in the GB300 NVL72 rack that supports a bare-metal OS instance
Rack	A physical arrangement of equipment, such as servers or switches in a vertical closet
Open Compute Project (OCP) Rack	Rack based on the Open Rack V3 standard from the Open Compute Project, with the vertical space divided up into 48mm units (OU) and with power distributed using power shelves, a DC bus bar and, AC power cords
Electronic Industries Alliance (EIA) Rack	Conventional “Enterprise” Rack, originally based on the EIA-310-D standard, with the vertical space divided up in 44.45mm rack units (RU) and with power distributed using rack power distribution units (rPDUs) and AC power
Tray	One of the systems inserted into the GB300 NVL72 solution, generally either a “Node” or a “NVSwitch” (which may include 1-2 NVSwitch ASICs) installed directly into a Rack
Hot Air Containment (HAC)	Refers to a set of racks that exhaust into the same hot-air containment area, generally from two opposing rows
NVLink Switch ASIC	The silicon building block with a specific logical port count that drives the network topology
Global Fabric Manager (GFM)	The external services that manage the fabric of a NVLink Domain
NVLink Domain	The full set of nodes connected with a single multi-node NVLink fabric
NVLink Block	A group of nodes within a NVLink Domain that are allocated to the same job. A single job may have multiple blocks assigned across multiple domains
NVLink Partition	A construct of group nodes within an NVLink Domain that are isolated to only access each other’s GPU memory. A partition could be configured as an entire domain or there could be multiple partitions in the same domain. Using partitions should protect interruptions to work running on one partition from the other partitions. Partitions are setup via API calls to the GFM.