I suspect that whatever has blanked out part of the system serial number in that picture, also partly covered a letter there. So, what you see as ITP, is actually 1TB (for a 1TB hard drive in the original configuration)
Machine Model: MacPro5,1
Family name: A1289
Group1: Mac Pro
Group2: nothing
Generation:
EMC number: 2629
CPU speed: 2.8GHz/3.46GHz
Colour: Aluminium
Production week : -29- (July)
Production year : -2012-
Model introduced: -2012-
Memory - flavour: xx
Memory - number of slots: 4
Factory: C0 (Quanta Computer (Subsidiary = Tech Com) China)