Arm64 dominates AWS Lambda in 2025: Rust 4-5x faster than x86, costs 30% less across all workloads

• Rust on arm64 completed CPU-intensive tasks up to 5x faster than x86
• Arm64 reduces cold start latency across all run times by up to 24%
• Python 3.11 on arm64 outperforms newer versions in memory-heavy workloads

Benchmarking of AWS Lambda this year shows that arm64 architecture consistently outperforms x86 across most workloads.

Tests covered CPU-intensive, memory-intensive, and light workloads across Node.js, Python, and Rust runtimes.

For CPU-bound tasks, Rust on arm64 completed SHA-256 hashing loops 4-5x faster than x86 Rust once architecture-specific assembly optimizations came into play.