2013 Mac Pro

that number covers Mac Pro 3.7GHz Quad core, 3.5 6-core, 3.0 8 core, and 2.7 12 core,

according to everymac.com

It could be either. One with a 3.0GHz CPU is 8-core, and the 2.7GHz units are 12-core.

(261690)

Just click on the Apple icon in the top menu, then click on "About this Mac" -- a window will pop up and give you a lot of info about the current Mac computer - of which the number of cores and their speed should be among the information displayed. Good luck...

-bob

Apologies for being late.

System Information (formerly "System Profiler" depending on the OS version) is better at showing the number of cores in both Intel and Apple Silicon Macs. In most macOS versions you can easily invoke it by holding OPTION while clicking the Apple menu icon. "About this Mac..." will change to System Information or Profiler. The hardware overview page has the core infor. This is from a 2010 iMac:

and from a 2024 M4 Pro Macbook Pro:

Note that a Late 2013 Mac Pro cannot run anything later than macOS 12 (Monterey), in case that matters.

Monterey fell out of "the most recent three" supported by vendors like Microsoft and Adobe a little over a year ago, when Sequoia came out.

Enquiring minds want to know...

What are you going to do with that information?

So are you storing that information away, or are you going to attempt upgrades immediately, or wait and see?