NVLink Multicast

NVLink multicast is an NVSwitch fabric capability. Start with NVIDIA NVSwitch for fabric context, then use the support tables on this page.

Important

NVLink multicast support requires that unified memory is enabled. For more information about enabling unified memory, refer to the Enabling Unified Memory for a vGPU documentation, or Unified Virtual Memory (UVM) for in-repo coverage.

See also

NVLink Multicast (on NVSwitch) on the NVSwitch page.

vGPU Support for NVLink Multicast

Only full-sized, time-sliced NVIDIA vGPU for Compute support NVLink multicast.

Blackwell

Table 61 NVIDIA NVLink Multicast Support on the NVIDIA Blackwell GPU Architecture

Board	vGPU
NVIDIA HGX B300	NVIDIA B300X-279C
NVIDIA HGX B200	NVIDIA B200X-180C

Hopper

Table 62 NVIDIA NVLink Multicast Support on the NVIDIA Hopper GPU Architecture

Board	vGPU
NVIDIA HGX H800	NVIDIA H800XM-80C
NVIDIA HGX H200	NVIDIA H200X-141C
NVIDIA HGX H100	NVIDIA H100XM-80C
NVIDIA H20 HGX 141 GB	H20X-141C
HGX H20 96 GB	NVIDIA H20-96C

NVLink Multicast Limitations

• NVLink multicast is supported only with full-sized, time-sliced NVIDIA vGPU for Compute profiles. MIG-backed vGPU profiles and fractional time-sliced profiles are not supported.

• Unified memory must be enabled for the vGPU. Refer to the Enabling Unified Memory for a vGPU documentation.

• NVLink multicast requires NVSwitch-connected GPU boards (HGX platforms). PCIe-only GPU configurations do not support NVLink multicast.

• Only the specific board and vGPU profile combinations listed in the support tables above are supported.