I just don't get how vSphere interprets cores and sockets.

I have a free licence with 2x E5-2670 8 core CPUs.

I want to use all 16 cores from both CPUs in one of my VMs.

The two config options, "CPU Cores" and "Cores per Socket" confuse me and I cannot get a combo of the two that will let me save it under the free license.  From what I read the free license should cover 2 sockets x 8 core CPUs.

Please help!