Saying XEONs are overkill depends entirely on the user and the intended task. For those at whom XEONs are
aimed, just one of them is almost certainly never enough, except for ANSYS perhaps. For GIS and many other
tasks, dozens at least are preferable. They're expensive because they do cost a lot to make (lots of cache
RAM on those things, and other logic for multi-socket links, etc.) and the target market can afford such pricing.
3K for a CPU is nothing when a complete system can easily be $1.5M. I have an old SGI in my garage which
was about that much when new in 1993 (24 CPUs, 2GB RAM, which in 1993 was enormous), used by various
car companies, oil/gas corps, etc., over the years, until I bought it used for a snip.
Ian.