The builtin Task Manager could show you the clock speed in real-time
Here for example (not from the V)
What you would want to see is the large “Speed” section, the one that says 0.99 GHz in that picture. The Core i7 model should be able to go to 3.6 GHz when needed, and slows down when not needed, to save battery.
All the other numbers are really not relevant for a Y processor configured with TDP-up in practice.
My Core m3 is rated at 1.00 GHz, and has the “Maximum Speed” of 1.60 GHz, but those numbers dont really do anything. 1.00 GHz is the minimum sustained-load clock when configured at 4.5W TDP, and 1.60 GHz is the minimum sustained-load clock when configured at 7W TDP. Thats the minimum clock guaranteed by Intel, but most, if not all V, could easily maintain 2 GHz in sustained loads, and up to 3.6 GHz (i7) in burst loads.