[DC] What Changed in AI Infra — Week 2026-W21

- **Power constraints overtake GPU supply as the primary AI infra bottleneck.** PJM power prices spiked 76%, Fed watchdog demands tech giants pay for grid upgrades, and post-approval data center delays now average 4 years. Nebius, CoreWeave earnings both flagged power procurement as the new gating factor, shifting the competitive axis from GPU access to energy contracts. - **Cerebras IPO defied GPU scaling orthodoxy with a 108% pop** to $385, signaling investor appetite for alternatives to Nvidia’s dense-GPU topology. The wafer-scale edge and tokenomics deals with AWS/OpenAI suggest a second-order shift: hyperscalers hedging against monolithic GPU clusters with disaggregated, wafer-scale architectures. - **Nvidia H200 sales cleared to 10 China firms**, reversing prior ban. Implication: U.S. export controls are becoming selectively porous, likely to maintain Nvidia’s market share against domestic Chinese AI chips—but geopolitical risk remains for hyperscale buildout plans reliant on future B200/B300 availability. - **B200 PD disaggregation yielded 7x token throughput improvement** and cost reduction, validating power-domain separation as a key architecture lever. This materially changes cluster design for 2025+ builds: expect more disaggregated power delivery in next-gen GPU pods, impacting both vendor selection (Nvidia vs. AMD/Intel) and facility electrical layout. - **SoftBank committed to water-based batteries for AI data centers by 2028**, and DOE funded 8 geothermal pilot sites. Second-order: long-duration storage and baseload geothermal are now concrete alternatives to natural gas peaker plants, potentially unlocking sites previously constrained by grid interconnection timelines. - **Satellite data revealed 37 new AI data center sites under construction globally**, while tariffs threaten $200B in planned buildout. The tension between rapid physical expansion and rising material/energy costs creates a bifurcation: well-capitalized operators (Meta, Nebius) proceed; smaller players face delays or site abandonment.