Question on assigning CPU's to a VM

I am setting up a Cisco UCS chassis.  According to vSphere client, I have 16 CPU's, 2 Processor Sockets, 8 Cores per socket.  I am planning on deploying up to 6 VM's per blade.  Based on that, I can assign 2 cpu's per vm, leaving 4 left over to assign depending on VM need/requirement.  To assign 2 CPU's per VM, do I assign 1 socket and 2 cores per virtual or 2 socket and 1 virtual per virtual ?  I get the same number of cores with either option.  I havent found a good explanation in the online help.

Ron