curated · 2026-07-05

The timeline is what makes this worth clicking: Jensen demoed Kyber NVL144 at GTC in March as Rubin Ultra's scale-out centerpiece, and now SemiAnalysis says it's pushed to 2028 with the NVL72x2 back-to-back rack design cancelled alongside it. If true, Rubin Ultra's scale-out story takes a real hit, which matters for cloud providers planning massive clusters next year. But this is just the first post in a thread — the body doesn't spell out whether it's a design issue, packaging yield, or supply chain snag. I'd wait for the rest of the thread before drawing hard conclusions.

The number is what makes this worth clicking: a single cluster over one gigawatt, with capex described as "hundreds of billions." For context, the largest publicly known training clusters today sit in the tens to low hundreds of megawatts. Prometheus would be an order of magnitude bigger. But the post is one sentence from Zuckerberg—no timeline, no chip specs, no PUE. I'd discount it until we see something concrete. A project at this scale has hard constraints: site selection, grid interconnection, cooling. Those don't get solved by a statement. If an environmental filing or power contract surfaces later, that's the real signal. For now, treat this as Meta's most aggressive infrastructure posture, not a confirmed build.