Sei Labs just published a whitepaper that reads less like an incremental improvement and more like a full engine swap. The Giga upgrade aims to push the Sei Network past 200,000 transactions per second with sub-400 millisecond finality, numbers that would place it in a performance tier that most Layer 1 chains haven’t even tried to enter.

For context, Ethereum processes roughly 15-30 TPS on its base layer. Solana, the current speed darling, has a theoretical ceiling around 65,000 TPS but real-world throughput that’s significantly lower.

What’s actually under the hood

The centerpiece of the Giga upgrade is something called the Autobahn consensus protocol. Traditional blockchains have one block proposer at a time, creating a bottleneck. Autobahn enables parallel block proposals, meaning multiple validators can propose blocks simultaneously without stepping on each other’s toes.

The whitepaper, published on May 19, 2025, outlines a target throughput of 5 gigagas. That’s a measure of computational capacity, and it represents roughly a 40x performance boost over Sei’s prior capabilities of approximately 5,000 TPS. The upgrade also introduces asynchronous execution, which decouples transaction ordering from transaction processing so the chain doesn’t have to wait for one step to finish before starting the next.

Sei’s roadmap breaks the work into three primary workstreams: execution, consensus, and storage. Together, these could enhance EVM throughput by up to 50 times, according to a detailed roadmap the team published in December 2024. The network has already demonstrated roughly 400ms block times on mainnet through what Sei calls Twin Turbo optimizations.

The path from here to there

Sei Labs hasn’t confirmed a fixed mainnet launch date for the full Giga upgrade. The current expectation is a rollout in the first half of 2026, with testnet phases for the SIP-3 migration scheduled for Q1 2026.

SIP-3 is a community-supported proposal to transition Sei into a purely EVM-compatible chain. Right now, Sei operates with both EVM and CosmWasm execution environments. Stripping down to EVM-only simplifies the developer experience and makes Sei directly competitive with Ethereum L2s and alt-L1s for Solidity developers. The target completion for that migration is mid-2026.

The Giga upgrade builds on Sei v2, which launched in July 2024 and introduced parallel execution capabilities.

“Sei Giga is not just another EVM chain. It’s a reimagining of what’s possible for blockchain performance.”

That’s Sei co-founder Jay Jog. The rollout timeline is also tied to developments in Minimum Extractable Value protections and AI tooling, with no fixed mainnet launch date confirmed as of May 2026.

What this means for investors

The 400ms block times already running on mainnet suggest the team isn’t building on vapor. A 40x improvement over a baseline of approximately 5,000 TPS is a more credible pitch than chains that promise moon-shot performance from a standing start.

Sub-400ms finality would make on-chain order books genuinely competitive with centralized exchange matching engines, which is Sei’s stated target market for high-frequency trading and DeFi applications.

For SEI token holders, the timeline creates a specific catalyst window. Testnet in Q1 2026, potential mainnet in H1 2026, and the SIP-3 EVM migration completing around mid-2026 gives the market a series of concrete milestones to price in or price out, depending on delivery.