Die yield
Fraction of functional chips per wafer. 90% yield = of 100 dies, 90 work. Larger dies → lower yield (one defect = whole die scrapped). Drives chiplet design + binning (selling defective chips as lower model).
Modern 3 nm nodes: early yield 60-70%, matures to 85-90% after years. Apple binning: M3 Pro defective GPU core → sell as M3 (fewer cores). Intel: Xeon defective cache slice → new SKU with smaller cache. Yield learning curves are trade secret — TSMC, Samsung, Intel don't publish exact figures. Yield determines price: H100 (814 mm² die!) has low yield → high prices. Consumer CPUs (smaller dies) better yield → lower price per unit.