Multicast is an efficient way of disseminating information and communicating over the network. Instead of sending a separate packet to every receiver, the sender sends one packet that is then distributed to every receiver that has subscribed to this multicast. Multiple receivers can be enabled on a single ESXi host only when you use multicast traffic. Because multiple receivers reside on the same host, packet replication is carried out in the hypervisor instead.

SplitRx mode uses multiple physical CPUs in an ESXi host to process network packets received in a single network queue. As it does not transfer the same copy of the network packet, it provides a scalable and efficient platform for multicast receivers. SplitRx mode improves the throughput and CPU efficiency for multicast traffic workloads.

Only the VMXNET 3 network adapter supports SplitRx mode. This feature is disabled on vSphere 5.0 by default; however, it is enabled in 5.1 and later versions by default.

SplitRx mode is individually configured for each virtual NIC.