The following figure shows the supported DIMM/memory configurations for R740xd vSAN Ready Node:
Figure 1. DIMM/memory configurations for R740xd vSAN Ready Nodes
The following figure shows the supported DIMM/memory configurations for R840 vSAN Ready Nodes:
Figure 2. DIMM/memory configurations for R840 vSAN Ready Nodes
Because of the strict SAP requirement for a symmetric homogeneous assembly of DIMMs, memory sizes such as 1,024 GB and 2,048 GB are not possible with the Intel Xeon-SP CPU architecture.
The sharing of CPU sockets between SAP HANA VMs, which is known as non-uniform memory access (NUMA) node sharing, is supported on two-socket and four-socket vSAN Ready Nodes. Only two production SAP HANA VMs per socket (half-socket) are allowed. The maximum number of production SAP HANA VMs on two-socket and four-socket servers is four.
With the NUMA architecture, each processor has its own local memory and can also access the nonlocal memory of the other processors over an advanced memory controller. Even though this is a high-performance connection, access to local memory is always faster than access to the nonlocal memory of the other processors. Take this into consideration when designing and configuring SAP HANA VMs under vSphere on PowerEdge vSAN Ready Nodes.