How does Sei's parallel transaction execution work and how does it benefit my dApps?

Sei's EVM implementation features a powerful Optimistic Concurrency Control (OCC) mechanism that enables parallel transaction processing, which is an advancement over Ethereum's sequential execution model.

How Parallel Execution Works in Sei

Sei uses a sophisticated transaction analysis and execution approach:

1. Transaction Grouping: The system automatically analyzes transactions to identify which ones can safely run in parallel based on state access patterns.

2. Optimistic Execution: Rather than forcing all transactions to execute one after another, Sei processes compatible transactions simultaneously across multiple threads.

3. Conflict Detection: The system tracks state read/write operations during execution to detect any conflicts between parallel transactions.

4. Conflict Resolution: If conflicts are detected, affected transactions are re-executed in a deterministic order to ensure consistency.

5. Finalization: Successfully executed transactions are committed to the blockchain in a deterministic order.

Benefits for Developers and Users

This parallel execution model provides several key advantages:

• Higher Throughput: Sei can process many more transactions per second than traditional sequential EVMs.

• Lower Fees: Increased throughput leads to reduced congestion and lower gas costs during high-demand periods.

• Faster Finality: Transactions confirm more quickly, improving user experience.

• No Code Changes Required: Your existing Solidity contracts work without modification - the parallelization happens at the protocol level.

Technical Considerations

When developing for Sei's EVM, keep these points in mind:

• Deterministic Results: Despite parallel execution, results are always deterministic - the same transactions will always produce the same outcome.

• Contract Interactions: The system automatically handles dependencies between contracts that interact with each other.

• Gas Model: While execution happens in parallel, gas accounting remains consistent with the Ethereum model.

• Flash Loan Protection: The parallel execution model has built-in protections against flash loan attacks that might exploit parallelism.

Performance Expectations

In real-world conditions, Sei's EVM can achieve:

• Throughput of thousands of transactions per second (multiple orders of magnitude higher than Ethereum)
• Confirmation times of less than 1 second
• Consistent performance even during high network activity

Best Practices

To maximize the benefits of parallel execution:

• Design contracts that minimize state overlap when possible
• Consider batching multiple related operations in single transactions
• Test throughput-sensitive applications under realistic load conditions