BlockSTM and MemIAVL Boosting Cronos Chain

### Performance

The efficiency of transaction execution is crucial for scalability and user experience for blockchain networks. High throughput (the number of transactions per second) and low latency (quick confirmation times) allow a smooth dApp experience even under heavy usage. To offer a better experience to users, the Cronos development team has worked diligently to optimize performance in order to meet growing demand. Two key innovations that have played a major role in enhancing transaction processing and state management on Cronos are BlockSTM and MemIAVL.

These innovations were co-contributed and designed to benefit the broader Cosmos ecosystem and have already inspired adoption elsewhere.

BlockSTM Overview

BlockSTM (block-level Software Transactional Memory) is a parallel execution engine that brings concurrency to transaction processing on Cronos. Traditionally, blockchain nodes process transactions sequentially, which can create performance bottlenecks. BlockSTM improves on this by allowing multiple transactions to be executed concurrently within a block. By leveraging STM, an optimistic concurrency control technique, BlockSTM ensures that conflicts are automatically handled and only rollback where necessary.

This parallelism makes better use of multi-core CPU resources, significantly increasing throughput and reducing latency. The Cronos team introduced a configurable benchmarking framework to evaluate the performance gains across different transaction types and environments. As shared in a previous post, in internal tests, the Cronos chain achieved throughput levels of up to 60,000 TPS, compared to a baseline of ~100 TPS. Even in multi-node configurations, the performance uplift remained substantial.

BlockSTM also reduces block processing time, which in turn supports lower block intervals and quicker finality. During benchmarking, it became apparent that the execution engine outpaced the load generator, indicating further room for growth with future tooling improvements. These findings are documented in the v1.4 benchmarking report.

MemIAVL Overview

While BlockSTM focuses on execution speed, MemIAVL (short for Memory IAVL) addresses the efficiency of state storage and commitment. In Cosmos SDK-based chains, the application state is traditionally managed by an IAVL tree. However, the original IAVL implementation can become a bottleneck due to the overhead of frequent disk writes and deep tree updates.

MemIAVL is an alternative implementationco-developed by the Cosmos and Cronos teams. It optimizes performance by storing working state in memory, using memory-mapped snapshots, and logging change sets via a write-ahead log (WAL). This dramatically improves the speed of committing state changes and restoring snapshots.

Tests showed that with MemIAVL:

• State snapshot restore times decreased from 16 hours to 5 minutes
• Block commit latency dropped over 10x
• Archived change sets are up to 100x smaller than full historical trees

MemIAVL is particularly well-suited for pruned nodes that do not retain full historical state. It works in conjunction with Cronos’s VersionDB, which handles historical data queries. For more details, refer to the MemIAVL documentation and repository.

A Collaborative Effort and Impact

Although the Cronos team initiated and implemented these technologies, they are designed to be modular and open. The Cosmos SDK community has shown interest in incorporating BlockSTM, and MemIAVL has inspired similar efforts. Notably, the Sei team adopted a MemIAVL-inspired design for their own state commitment layer.

Cronos’s implementation of BlockSTM and MemIAVL is available as open source in the BlockSTM Codebase, Benchmark Results, and MemIAVL Documentation. These contributions aim to strengthen not just Cronos but also help lay the groundwork for performance improvements across other Cosmos SDK chains.

For developers and ecosystem partners, the benefits are clear:

• Higher throughput enables high-volume applications like DeFi trading platforms or real-time games
• Lower latency improves the user experience for applications needing fast finality
• Faster node sync reduces operational burden for infrastructure providers
• Improved RPC performance accelerates development and debugging workflows

These enhancements empower developers to build more responsive and scalable applications directly on Cronos, without depending on external scaling solutions.

Conclusion

BlockSTM and MemIAVL represent important steps toward solving core performance challenges in blockchain infrastructure. Through open collaboration and community-oriented development, the Cronos team is proud to contribute to the Cosmos ecosystem’s technical advancement. These innovations exemplify how deep protocol-level improvements can enable a new wave of dApps and expand the potential of Web3 infrastructure.

We encourage Cosmos ecosystem developers and chain operators to explore, test, and contribute to these initiatives. Together, we can build a faster and more efficient decentralized future.

BlockSTM and MemIAVL Boosting Cronos Chain was originally published in Cosmos Ecosystem Blog on Medium, where people are continuing the conversation by highlighting and responding to this story.