The developers of the BNB Chain blockchain ecosystem based on the BNB coin have launched a testnet of the second-level network called opBNB.

opBNB is an Ethereum Virtual Machine (EVM) compatible BNB Chain scaling network based on the Optimism OP stack. The network uses Optimistic rollups to increase scalability, increase transaction speeds and reduce fees.

Currently, the throughput of the first level of BNB Chain is about 2,000 transactions per second (TPS), and the average transaction cost is about $0.109. The opBNB solution will support more than 4,000 TPS, and the cost per transaction will be less than $0.005, said Arno Bauer, senior solutions architect for BNB Chain.

The opBNB mainnet is expected to launch in the third quarter of 2023. It will complement the already existing networks of the BNB Chain ecosystem:

  • BNB Smart Chain is a blockchain for smart contracts, on the basis of which all DeFi solutions are created.

  • BNB Beacon Chain is a blockchain for ecosystem management and staking.

  • BNB Greenfield is a centralized data storage system.

  • zkBNB - L2 solution using zero-knowledge proof.

When asked why BNB Chain is launching another L2 solution, Bauer replied that zkBNB is not compatible with EVM, but opBNB is compatible. EVM compatibility means that applications built for Ethereum can easily run on another network as well. EVM compatibility is important because it allows developers to easily port their Ethereum-based applications to another network and thus quickly expand its capabilities.

Now that there are zkBNB and opBNB, BNB Chain can fully compete with the ecosystem of L2 solutions for Ethereum, such as Arbitrum and Optimism, Bauer noted. The opBNB block gas limit is set at 100 million, while Optimism's is at 30 million. The higher gas limit is aimed at network usage in the GameFi, DEX, and digital collectibles sector. The developers see the following situation as an ideal option: opBNB is used as a specialized high-performance registry for gaming applications, and BSC is used as a secure blockchain for settlements.