Aptos Node Release Makes Block-STM v2 the Default Execution Path

Aptos’ v1.49.1 node release makes Block-STM v2 the default execution option for operators without a custom override, while staged deployment means the software change does not establish broad validator adoption.

The default was merged into Aptos’ codebase June 22 and included in the mainnet-tagged release published Sept. 23. TokenPost previously covered the broader v1.49.1 node update.

Aptos first deploys a node release across 1% of mainnet stake, then announces it more broadly as other validators gradually upgrade. Timing varies by release. Operators who install v1.49.1 without changing the setting get the new default, but the release itself does not show how far upgrades have progressed across validators.

Block-STM executes transactions speculatively in parallel, then checks their results against a preset order. If a transaction fails validation, the engine runs it again. The goal is to run independent transactions concurrently while preserving the result that the preset sequential order would produce.

Block-STM v2 was designed to scale across machines with 256 cores. That is a design target, not a measured v2 result. Parallel execution is relevant to decentralized finance applications where transactions can compete for shared data, but the v1.49.1 change does not quantify performance gains for those workloads.

A 2022 benchmark of the original Block-STM reached up to 170,000 transactions per second with 32 threads, or 17 times the sequential baseline. The test measured execution with an in-memory database rather than end-to-end performance on a live network. The v1.49.1 change record reports no v2 throughput result or measured effect on transaction fees.