IOG, the engineering firm behind Cardano's core protocol, reported that the Musashi Dojo testnet reached a peak of 26.8 transaction kilobytes per second (TxkB/s) during its opening phase. That figure is roughly six times the current Cardano mainnet baseline of about 4.51 TxkB/s under Ouroboros Praos, the protocol powering the live network today. The testnet ran for 41 days after its June 23 launch and processed 18 times the transaction count of real mainnet activity, at 3.3 times the data volume.

What Leios Actually Does

Ouroboros Leios is not a replacement for Praos. It operates as an overlay that activates during high demand. The core inefficiency it targets is straightforward: Cardano produces a new block every 20 seconds, but that block propagates across the network in roughly 5 seconds, leaving the system idle for the remaining 15. As IOG has stated directly, "The system is idle roughly 75% of the time."

Leios fills that idle window using a second type of block called an endorser block (EB). Endorser blocks are produced approximately every 5 seconds by committee lottery winners, reference large batches of user transactions, and are validated by rotating, stake-weighted committees rather than by a single block producer. A committee must reach a 75% stake quorum before an EB is certified, and those certificates are then embedded into standard Praos blocks to finalize ordering.

On stable days during the testnet, Leios traffic accounted for 54% of all on-chain activity.

The Earth phase, now complete, was focused on verifying that the basic protocol behaved correctly. It produced more than 127,000 blocks, 30,000 endorser block announcements, and roughly 8,000 on-chain certificates. Forty of the 63 registered stake pool operators participated at peak. IOG shipped 12 software releases across 8 weeks, including two same-week hotfixes.

Security and What Was Not Found

IOG reported no compromises to the Praos layer and said that when nodes underperformed, the degradation scaled proportionally to their stake rather than cascading into broader chain failures.

"Every problem we found was a bug in our code, not a flaw in the protocol, and we fixed each one in public on a weekly release cadence," IOG wrote in its summary. "Nothing so far threatens the safety of the underlying Praos layer, and performance degraded in proportion to stake rather than breaking the chain."

It is worth noting what this phase was not: formal adversarial testing. That is reserved for Phase 4, called Wind. Earth was designed to confirm basic correctness, and it did.

Where the Protocol Stands Now

The Musashi Dojo testnet takes its name from Miyamoto Musashi's Book of Five Rings, and each of its five phases corresponds to a chapter of that text.

Earth is complete. Water is now active, introducing parameter exploration, testing of alternative Leios implementations by teams outside IOG, and a live incentive program for stake pool operators.

Fire will follow with high-load stress testing. Wind brings adversarial scenarios. Void is reserved for final mainnet preparation.

IOG is targeting a mainnet deployment by end of 2026. The ceiling figures in the formal Cardano Improvement Proposal, CIP-0164, project a potential range of 140,000 to 300,000 transaction bytes per second (TxB/s) at full parameterization, a 30 to 65 times increase over today's baseline. Note that the testnet result is expressed in transaction kilobytes per second (TxkB/s), while the CIP-0164 ceiling uses transaction bytes per second (TxB/s); these are different scales and the two figures should not be compared directly. The ceiling numbers represent the protocol specification's upper bound, not a tested result.

Funding, Governance, and Regional Stakes

Development costs are being covered by a community treasury allocation of 27.7 million ADA, approved by Cardano token holders with 88% support under the network's Voltaire governance framework.

The Cardano treasury now holds more than $1 billion in ADA, and the Leios vote is among the first major protocol funding decisions to go through on-chain governance at that scale.

The practical stakes extend well beyond North American or European markets. Cardano carries one of the most active Africa-focused footprints among major Layer 1 blockchains, with roughly 150 Africa-focused Catalyst projects funded, a $30 million developer grants program launched in early 2026, and events like the Cardano Africa Tech Summit drawing more than 500 developers across 12 cities.

Many of those projects involve batch processing of small transactions for agricultural supply chains, educational credentials, and humanitarian logistics.

These use cases run directly into Praos throughput limits during peak activity.

The congestion problem is not theoretical. The Midnight Network, which distributes NIGHT tokens to ADA holders, deliberately stretched its Glacier Drop across four 90-day phases spanning December 2025 through December 2026. Among the stated reasons for the extended timeline was a desire to avoid network congestion.

It is an example of a major ecosystem project self-throttling to fit within what Cardano can currently handle.

South Asia and the Path to Scale

The throughput constraints Leios addresses carry equal weight in South Asia, where Cardano has a growing developer presence. EMURGO, one of Cardano's three founding organizations, hosted a Cardano Hackathon at India Blockchain Week in Bangalore, drawing builders focused on micro-transaction rails and remittance applications well suited to the region's large unbanked population. For South Asian developers evaluating Layer 1 platforms, Cardano's competitiveness against Ethereum and Solana in the DeFi space depends in part on the throughput headroom that Leios is designed to open. The Water phase's global stake pool operator incentive program is structured to attract a broader set of international node operators, including those based in South Asia, ahead of mainnet deployment.

Market Context

ADA traded at approximately $0.226 at the time of publication, with a market capitalization near $8.47 billion (ranked 17th). Cardano's DeFi total value locked stood at approximately $54.35 million as of August 20, 2026, a figure that underscores the throughput constraints Leios is designed to remove.

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ADA price and market data sourced from CryptoRank and CoinGecko as of August 25 to 27, 2026. DeFi TVL figures sourced from The Crypto Basic as of August 20, 2026. Primary protocol reporting sourced from Olga Hryniuk, IOG Official Blog, August 27, 2026.