Should you buy a 3990X for rendering in blender?

When the 3990X dropped in February of this year, it certainly landed with a thud. But is it a good purchase for rendering? Is that even a sane question when its clear its faster than anything else out there CPU-wise right now? Assuming you're thinking about purchasing either a new workstation, or perhaps even building a render farm. After crunching numbers, I have some insights I'd love to share to answer these questions :)

In this article

A comparison of the 3990X along side the fastest rendering CPU's out there, the focus is on raytracing, particularly in cycles, we'll be looking at;

How each CPU performs and where the 3990X sits in the pack

How to determine a measure of value to compare each CPU against