What does this equation mean?

It is worth being explicit about what this standard does and does not guarantee. UCIe compliance means two chiplets can establish a working electrical link and exchange PCIe- or CXL-framed traffic across it — it is an interoperability floor, not a performance ceiling, and not a guarantee that any two arbitrary UCIe-compliant chiplets will perform well together. A retimer mechanism exists in the specification specifically to extend UCIe connectivity beyond a single package using off-package electrical or optical links, with each retimer implementing a full UCIe interface on its own local side and independently negotiated buffer credits — a detail that matters because it signals the standard’s authors anticipated multi-package, not just single-package, chiplet topologies [ 1 ] . Whether that extended, off-package use case sees real deployment volume is a separate, open question this standard’s existence does not settle. This relation is not a UCIe-published formula; it is included here only to make explicit why bump pitch appears so often in vendor and standards disclosures as the headline number. For a fixed die edge length available to a module, halving the bump pitch roughly doubles the number of lanes that fit across that edge, and bandwidth scales accordingly — which is exactly why the standard defines separate pitch tiers for standard versus advanced packaging rather than one pitch for both.