Maximum speed of pmsm motor from Kv

[swatHuman]

Hello Everyone!

I was wondering if it is possible to find the maximum achievable speed of a brushless motor by looking at the Velocity constant Kv?
Looking at a few definition of Kv here:
https://en.wikipedia.org/wiki/Motor_constants

Kv = W(no-load) / Vp

Could you please explain what is Vp here? is it the peak voltage measured across one phase to another phase of the motor? OR is this phase to neutral(midpoint of the star connected motor load)?

Also I found this thread that has a different formula:
https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1271711/mcf8315a-speed-control-issue
Electrical Speed = (DC/sqrt(3)/(Back Emf in mV/Hz))*1000
Could you please explain if they are the same?