Could this cause multiple identical GUIDs?

Question

As GUID generation is time-dependent, if System.Guid.NewGuid() is called multiple times at the exact same instant on different threads, could it return identical GUIDs?

Answer 1

No, there is a serial number inside it that changes for each call, so multiple simultaneous calls on different threads on the same system will not create duplicate Guids.

That does not mean that there is a visible part of the Guid that you can see increments for each call.