I have been reading some tutorials about power consumption on parallelized system. I have been following this tutorial.

https://www.youtube.com/watch?v=cMWGeJyrc9w&list=PLLX-Q6B8xqZ8n8bwjGdzBJ25X2utwnoEG&index=2

At about 3:50 min of this tutorial, the mentor mentions that.

lets say if I have a processor that operates at frequency f.

The output power is $$CV^2f$$

Where V is the voltage, and C is the capacitance.

If we have the two processors that operate on the frequency f/2, and they are connected in parallel. Then total output power will be P1 + P2. And for each of the processor, voltage will be V (they are in parallel). And the Capacitance will be 2C (C1+C2) for parallel.

So total power will again be:

P = P1 + P2 = $$ 2( CV^2 f/2) $$ 

Which will again be equal to 

$$ CV^2f $$.

But the mentor mentions that the power consumption will be decreased by 40%.

Can anybody explain do multi core reduce the power consumption by such a high value?