So, Mike – a Mango reader – emailed me with this question a few days ago: ​

“ Hey Shawn, I enjoyed your explanation on Sharding. Thank you. But now I’m trying to understand what makes Proof Of Stake less resource intensive than Proof Of Work? Doesn’t the verification process need to take place the same way? ”

This is actually a really good question, Mike! It shows that your understanding is growing deeper. Your asking the right questions! Yes, PoW and PoS conduct the validation/verification of transactions similarly. As such, Proof Of Stake consumes just as much resources to verifiy transactions as Proof Of Work does. However, it’s important to note that the “verification of transactions” is not what makes Proof Of Work resource intensive. It is the Cryptographic Puzzle – required to be solved by all miners – that consumes a large majority of the resources.

The PoW Puzzle – The Real Resource Hog

Many of us tend to believe that it's the validation of transactions consumes the resources. In truth, the majority of the resources is consumed while solving the Cryptographic Puzzle - which has nothing to do with the validation/verification of transactions. In fact, Proof Of Work and other consensus methods are more concerned with the ordering of transactions than the "validation" of transactions. The ordering of transactions is resolved by getting miners to solve the Cryptographic Puzzle. Miners solve the cryptographic puzzle in order to win the “right” to place their block next on the chain. And it’s the solving for the "cryptographic puzzle" that is computationally intensive - not the verifications transactions.