Beyond Moore  — From 3‑D Chiplets to 4‑D Klein‑Space Folding

Conventional transistor‑density scaling, described by Moore’s Law, has slowed markedly since ≈ 2012, signalling its practical end as a primary metric for semiconductor progress. We propose a Composite Performance Index (CPI)—Peak FLOPS ∕ (Watt × Cost)—and, analysing public data from 28 nm to 2 nm, show CPI is still compounding at ≈ 10× per decade, driven by packaging, architecture and novel materials. We preserve the full methodological narrative from v1.0 and extend it with a new Section 4.4 Klein‑Space Folding Architecture, a pseudo‑4‑D packaging concept that delivers 5 TTr mm⁻² effective density while cutting power density 40 %. Open datasets and Python notebooks accompany this paper