CPO is a bet on more than a dozen paths: the Big Four enter via scale-up, switch silicon, custom engines and optical I/O, while challengers stake out optical I/O chiplets, photonic interposers and microLEDs. But they share one supply chain — great specs don't guarantee a path to volume. This is a CPO scorecard.

At FMS 2026 Marvell unveiled a trio of memory products, and the market read it as another wave of AI launches. Put them in the context of four acquisitions, though, and the real play is owning the entire "data movement layer" — memory is just the first toll. We break down the map, the moat and the supply chain positioning.

Jensen Huang declared that "compute has been disaggregated"; Matt Murphy supplied the missing physical timeline. AI's next bottleneck is connectivity, and the deciding factor is a copper wall moving into the rack. Every doubling of bandwidth halves copper reach — at 400G/lane, copper can't even span a single rack, and physics forces CPO from slideware into shipments.

Why did Marvell pay up for Celestial AI? The answer is the SiPh interposer, which turns the PIC into an active interposer between GPU and HBM: the endgame architecture for scale-up CPO. Lightmatter runs an independent track, and neither uses TSMC. Part 4 of the series unpacks this underrated long-term axis.

Marvell's $3.25B Celestial AI deal is not another CPO startup buy. What it really paid for is Photonic Fabric, which brings light into the center of the die and breaks the memory wall: a ticket to whatever replaces copper inside the package.