Since its mainnet launch in August 2023, Sei Network has rapidly evolved into one of the fastest Layer-1 blockchains, underpinning a boom in on-chain gaming, DeFi, and new financial primitives. In Q1 2025, the Sei ecosystem recorded 354,000 average daily gaming transactions (up 79.8% QoQ), with total value locked (TVL) surging 73.7% QoQ to $363.1M.

Fueling this momentum is Sei’s relentless focus on technical innovation. Everyone's Eye on anticipated "Giga" upgrade, which targeting a 50x improvement in throughput over existing EVM-compatible networks and a theoretical maximum capacity of five gigagas per second (with up to 250,000 TPS). This deep dive explores how Sei Giga, by pushing the boundaries of parallelization and consensus, is poised to reshape the landscape for MoveVM-based chains and high-performance blockchains as a whole.

The State of Fast Chains: Parallel Execution and Key Players

Parallel execution is now a prerequisite for blockchains aiming at mass-market applications and ultra-low latency use cases. Chains capable of transaction parallelization, where non-conflicting transactions execute simultaneously. It helps achieve far greater throughput and lower congestion than their sequential peers.

Landscape Overview

Sei and Solana demonstrate the power of parallelization, with Solana's Sealevel VM and Sei’s use of dependency mappings and optimistic parallelization to isolate and process independent transactions concurrently. 

Meanwhile, Aptos and Sui leverage the MoveVM for object-centric parallelism, tightly grouping transactions by "object" and routing them to validators for concurrent execution. 

However, classic EVM chains like Ethereum remain largely sequential, which limits throughput. Recent L2s and new L1s (Monad, MegaETH) are attempting to bridge this gap but still lack the combined ecosystem and mindshare of established platforms.

Sei Giga: Architecture and Innovations

What Is Sei Giga?

Announced in December 2024, Sei Giga is a major upgrade engineered to reimagine EVM performance via radical improvements in throughput, latency, and developer experience. The upgrade focuses on delivering:

  • 5 gigagas/second compute capacity (with a target of ~250,000 TPS)

  • Intelligent parallelization: Predicts transaction dependencies, maximizing the pool of non-conflicting parallel transactions

  • First-ever multiple concurrent proposers on an EVM Layer-1: Validators can submit blocks simultaneously, shattering bottlenecks in block production

  • SeiDB re-architecture: Overhauls storage for faster sync and state updates (up to 287x faster block commits, 60% reduction in state storage size)

  • Optimistic parallelization: All transactions are assumed parallel-ready; those with conflicts fall back to sequential processing

  • Revamped execution, consensus, and storage workstreams: Each redesigned for horizontal scalability

How Does It Work?

Sei Giga’s core innovation lies in decoupling consensus (transaction ordering) from transaction execution, allowing block production and validation to occur independently. Combined with predictive transaction dependency mapping (akin to how Sui/Aptos MoveVM handles objects), the system aggressively parallelizes workloads, achieving best-in-class throughput without sacrificing finality or security.

Step-by-Step: How Sei Giga Works

After understanding Sei Giga’s architecture and innovations, it’s important to break down exactly how these major upgrades work step by step. Below is a walk-through that bridges both a technical and general needs:

1. Transaction Receipt & Compatibility

  • User submits a transaction: Whether through a dApp, wallet, or other front-end, a user interacts with a smart contract or sends tokens, signing an Ethereum-compatible (EVM) transaction.

  • Sei RPC interface: The transaction enters the network and is immediately translated into a native Sei format, ensuring seamless compatibility with the EVM environment. This step ensures developers and users have familiar tooling, while benefiting from Sei Giga’s underlying speed.

2. Parallel Processing & Optimistic Parallelization

  • All transactions assumed parallel by default: Unlike legacy systems that only parallelize with explicit developer input, Sei Giga “optimistically” assumes all transactions can be executed in parallel. The system examines whether transactions interact with overlapping state (e.g., same wallet balances, contracts). If not, they’re safely executed simultaneously to maximize throughput.

  • Conflict detection and fallback: If a group of transactions does interact with the same state, they’re rerun and validated sequentially in a deterministic order until all conflicts are resolved. This means user experience improves (faster, more reliable execution), while developers don’t need to code special logic for parallelization.

    Technical note: This process leverages a dependency-mapping engine—akin to a directed acyclic graph (DAG)—to map and schedule transaction execution in real-time.

3. Multi-Proposer Autobahn Consensus

  • Multiple block proposers: Typical blockchains designate a single validator to propose each new block. Sei Giga introduces “Autobahn,” a consensus model where multiple validators (proposers) can simultaneously submit blocks, each operating in separate “lanes.” This allows the network to process and reach consensus across several blocks in parallel.

  • Data availability and snapshots: Each “lane” generates proofs of data availability. Periodic “cuts” (snapshots of each lane’s head/tip) are aggregated for network-wide consensus on block ordering, decreasing time-to-finality and boosting system-wide throughput.

  • Result: Block production is no longer bottlenecked by sequential proposer rotation; instead, it’s pipelined and parallelized.

4. Asynchronous State Commitment & Execution

  • Separation of ordering and execution: In most networks, transaction ordering and execution are tightly coupled, meaning blocks can’t be processed until ordered, executed, and verified. Sei Giga decouples these steps: blocks are finalized based on transaction ordering first, while execution happens asynchronously. State roots are then committed in subsequent blocks.

  • Advantage: Validators continue producing new blocks even while previous ones are still being executed. This approach is inspired by high-performance computing (e.g., Block-STM) and supercharges time-to-finality.

5. Advanced Storage: SeiDB V2

  • Flat key-value storage: Sei Giga’s new storage architecture replaces the Merkle tree with a flat key-value system, optimized for RAM and asynchronous disk access. This allows for orders of magnitude faster state access and writing, crucial for supporting the increase in throughput.

  • Separation of hot/cold data: Frequently used (hot) state is kept on fast SSDs/RAM, while older (cold) data is offloaded to a distributed database, significantly reducing active state size. Commitments use cryptographic accumulators for fast, verifiable consensus.

  • Performance gains (Q1 2025): 60% reduction in state storage, 12x faster state sync times, 287x faster block commit, 2x higher throughput, and 90% reduction in archive state size.

6. Proof-of-Stake Security & Governance

  • DPoS mechanism: The core consensus engine is Delegated Proof of Stake (DPoS), with SEI as the native token used for fees, staking, and validator rewards. Community governance allows SEI stakers to vote on network upgrades, including parameters relevant to Giga.

7. Developer & User Impact

  • For developers: No need for custom parallelization logic; the network optimistically manages it. EVM compatibility makes it easy to port Ethereum dApps to Sei.

  • For users: Ultra-fast confirmation, minimal fees, and a seamless experience even during network congestion.

How Sei Giga Differs: Real Metrics and Comparative Analysis

Performance Metrics

Sei Giga (Devnet, Q1 2025)

  • Achieved 5.4 gigagas/sec (~115,000 TPS) and 700ms time-to-finality in internal tests

  • Targeting 250,000 TPS post-mainnet with 5 gigagas/sec capacity

  • TVL surged 73.7% QoQ to $363.1M post-Giga launch

  • Daily DEX volumes up 234.4% QoQ to $19.1M

Parallel execution is a great meta to look after. We already have some decent players in this space: Move (SUI & APTOS), NeonEVM, and of course, Sei itself. However, the recent upgrade is truly impactful and marks an upcoming dominance for Sei Giga. Although transaction speed alone doesn't fully define a great chain, it does demonstrate what the next generation of Web3 looks like: instant finality, near-instant transactions, and almost no congestion.