Agentic AI in EDA: Cadence, Synopsys and Siemens claim L4–L5 autonomy

The three dominant chip design software vendors — Cadence, Synopsys and Siemens EDA — added reasoning models to their EDA agents in 2026. Cadence claims "bounded Level 5" for ChipStack, Synopsys claims L4 for spec-to-RTL and L5 for long-horizon agents, and Siemens touts self-verifying loops. All speedup figures come from vendors or their customers, with no independent evaluation.

• Cadence ChipStack: RTL validation over 40x faster, cutting a five-week loop to under a day
• Synopsys: up to 50x faster RTL validation with 20% coverage improvement over non-agentic flow
• Siemens Questa One Agentic Toolkit has five agents and works with Claude Code and Cursor
• All claimed speedups are vendor or customer figures without independent verification