What TPS Really Measures in Blockchains — and When It Misleads

TPS is not a property of a blockchain — it’s a function of configuration and workload. Block size, block time, transaction complexity, execution model, and load submission strategy can all dramatically change TPS without altering the underlying architecture. In controlled experiments on Substrate, TPS increased by removing safety margins, shortening block time, and batching transactions — not by redesigning the execution engine. This shows how easily TPS numbers can be inflated. TPS is useful as an internal engineering metric for comparing configurations within the same system, planning capacity, and detecting performance regressions. Outside of fixed assumptions and normalized workloads, TPS comparisons across blockchains are misleading and often meaningless.