I would contact your sales person about this.
Heya Paul -
If the OS presents 12 cores to a Tableau Server licensed at 8 cores, it won't even start. You'll get a licensing error message.
Most people handle this in one of two ways:
- Disabling x (4, in your case) cores in the BIOS
- Running Tableau Server under a VM on the box and only presenting the VM with 8 cores
The first technique "wastes" hardware in cases where you have other things running on the machine - the second allows you to run all your cores, but you pay the "virtualization tax" and lose a tiny bit of performance from the app running in the VM - in this case, Tableau Server.
Re. the number of cores on the OS presents, It will be confused on modern cpu that has multi-threaded capability that means OS will present 2 times number of cpu cores as number of threads. Intel website of xeon spec will report correctly as #cores and #threads (as well as multi-threaded yes/no)
But could Tableau Server recognize those different correctly?