Vitalik Buterin once again explain how Ethereum solves the problem of scalability. It is about second layer solutions Sharding and Plasma.
Sharding means that a blockchain network is splits to shards which are then equipped with a group of nodes. Their tasks are to process information of certain shards. With Sharding enabled, all nodes on the blockchain are not required to process every single piece of data settled on the blockchain. That leads to optimizing of the process of settling information.
Plasma is not about speed but security too. This solution is developed by Buterin and Joseph Poon, who is Lightning Network for Bitcoin blockchain co-author. Plasma enables Ethereum to process micropayments by creating child blockchain networks within the main blockchains. This results in processing information more swiftly, leveraging the security of the main Ethereum protocol. No doors to potential attacks.
As Vitalik said, each of two improvements gives 100x speed rise. And “the scalability gains from the layer 1 improvements and layer 2 improvements do ultimately multiply with each other”. So Ethereum would be increased by 10,000x due to “synergy between layer 1 and layer 2 solutions”. In such way 1 mln Tx/sec is real.