Cloud Assembly template code lets you specify a number of cores per socket for a vSphere machine resource.

You can specify the number of cores per virtual socket or the total number of sockets. For example, your licensing terms might restrict software that is licensed per socket or available operating systems might only recognize a certain number of sockets so that additional CPUs must be provisioned as additional cores.

Add the coreCount property to a cloud template in the vSphere machine resource.

The coreCount value must be less than or equal to the CPU count (cpuCount) value specified in the flavor mapping or in the vSphere machine resource code in the cloud template. For related information, see Setting the number of cores per CPU in a virtual machine (1010184).

The coreCount property is optional and available only for vSphere machine resources.

An example vSphere machine resource snippet is shown below.
Cloud_vSphere_Machine_1:
  type: Cloud.vSphere.Machine
  properties:
    cpuCount: 8
    coreCount: 4

Additional information about sockets and cores per socket settings is available in blog article Virtual Machine vCPU and vNUMA Rightsizing – Guidelines.