I'm pretty sure that post #2 is correct, although I haven't been able to find a Microsoft link to that.
Another way of putting it: physical CPUs = sockets.
I wonder why the OP didn't upgrade to Win 10 Pro. To have run dual sockets in 8.1, the machine must have had 8.1 Pro installed.
I was thinking about something else when I wrote the post. I had Win7 Ultimate installed and that showed all my sockets. I have since re-installed everything (since my start button refused to work) and put Pro on it. Now all RAM and sockets are being used.
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