TL;DR
SemiAnalysis published "Datacenters 2027: The Year of Acceleration" on October 25, projecting about 51.2 GW of new data center IT capacity outside mainland China in 2027, more than double the 25 GW expected in 2026. The report also argues that chips and HBM will return as the primary bottleneck in 2027-2028 as power and construction constraints ease.
Event Overview
On October 25, 2026, semiconductor research firm SemiAnalysis released a report titled "Datacenters 2027: The Year of Acceleration." The report projects that new data center IT capacity outside mainland China will reach about 51.2 GW in 2027, more than double the 25 GW expected in 2026 and more than triple the 15.6 GW of 2025. SemiAnalysis directly characterizes 2027 as an "acceleration year" for AI data center buildout.
Key Information
| Item | Data |
|---|---|
| 2027 projected new capacity (excl. mainland China) | About 51.2 GW |
| 2026 new capacity | About 25 GW |
| 2025 new capacity | About 15.6 GW |
| Capacity under late-stage construction | Over 24.3 GW (about 40 campuses) |
| Data center leases signed in 2026 YTD | Slightly below $1 trillion |
| Behind-the-meter power reservations (Aug 2026) | 75 GW |
| Behind-the-meter equipment suppliers | 22 |
Three Pieces of Evidence
SemiAnalysis responds to market skepticism about AI infrastructure delivery with three measurable indicators:
- Satellite imagery: Over 24.3 GW of data center capacity at about 40 campuses worldwide is in late-stage construction, with most projects more than half complete and expected to deliver within 2027.
- Lease contracts: Binding, non-cancellable data center leases signed globally in 2026 YTD total slightly below $1 trillion. Meta, AWS, Microsoft, Google, NVIDIA, AMD, Anthropic and OpenAI are all seeking gigawatt-scale leases; Oracle completed about 4.5 GW in the second half of 2025.
- Self-build starts: Quarterly megawatt starts by U.S. hyperscalers are growing in a parabolic pattern.
Divergence and Bottlenecks
The report arrives as debate over the AI infrastructure boom intensifies. At the All-In Summit in September 2026, Altimeter Capital founder Brad Gerstner publicly challenged SemiAnalysis's earlier 43 GW forecast, arguing actual delivery in 2027 would be closer to 25 GW. SemiAnalysis responded in the report: "We focus on facts, not narratives."
The report notes that completing a data center does not mean filling it with GPUs on day one. As power and construction constraints ease, SemiAnalysis expects chips and high-bandwidth memory (HBM) to return as the primary bottleneck in 2027-2028.
Official Sources
- SemiAnalysis "Datacenters 2027: The Year of Acceleration" (published October 2026), as reported by Xinzhi Times via Sina Finance on October 25, 2026 link