Bandwidth density
Beginner
How much data can cross between chips for each millimeter of chip edge you use for connections.
Novice
Bandwidth per unit of die edge (GB/s per mm of shoreline) or per unit area (GB/s per mm²). It is the number of connections in that space times the data rate of each.
Expert
Shoreline density = signal bumps per mm² × bump-field depth × lane rate. Areal density matters for 3D, where the whole overlap can carry bonds. UCIe’s targets span about 22–125 GB/s/mm² (standard), 188–1,350 (advanced) and about 4,000 at 9 µm hybrid bonding.
Explained in Packaging and chiplets (Systems).
See also: Bump pitch, Shoreline (beachfront).