Inside the 800G → 1.6T → 3.2T Race
Timing is everything. What the industry said about 800G, 1.6T, 3.2T in recent earnings calls
The AI interconnects supply chain is fascinating right now. The industry is doubling per-module bandwidth (800G → 1.6T → 3.2T), and every doubling is a new industrywide race. Who can get there first for the next hyperscaler datacenter build?
There are physical limits at higher bandwidths too, and that changes what technologies matter over time. EMLs, SiPh, VCSELs, AECs, ACCs, AOCs, microLEDs, etc.
On top of that, capacity constraints are in play (e.g. InP wafers), so decisions made 18–24 months earlier determine who can actually ship when the doubling lands.
Timing is everything.
But there’s a lock to unpack. Where to start? Let’s wrap our heads around the cadence the industry is chasing by reading recent earnings call from the public semis, optics, networking, and contract manufacturers in the stack.
Here’s what they laid out, at the highest level:
400G: mature.
800G: volume cycle in 2026 and 2027.
1.6T: production scale in 2027.
3.2T: launching in 2028, volume ramps 2029–2030.
In chart form:
One caveat on reading the chart. We have to infer the mix shift ourselves. No CEO says “our 400G sales are declining” on the call.
So that chart captures the cadence at the highest level, as decoded from ~15 companies’ earnings calls. But there’s a ton of nuance to unpack. First, there are differences between roadmaps for scale up/out/across. Plus, the further out stuff is fuzzy, so we should compare what the CEOs optimistically said against actual OFC (R&D) announcements.
For paid subscribers who want to go deep, we’ll hit on
Year by year: Scale-out, Scale-up, Scale-across
The receipts. ~50 direct CEO quotes from ~15 companies grouped by generation and year
Timing nuances, especially 3.2T
OFC 2026 reality check
We’ll also check back in quarterly to see how the communicated roadmaps change.