TL;DR
This dataset compiles the core figures from SemiAnalysis's "Datacenters 2027: The Year of Acceleration" (released October 2026), covering new capacity forecasts, construction progress, lease scale, build efficiency and forecast divergence. All values follow the report and media coverage of it.
Data Notes
Data source: SemiAnalysis report "Datacenters 2027: The Year of Acceleration" (published October 2026); media coverage via Xinzhi Times on October 25, 2026. Capacity is in gigawatts (GW). The "excl. mainland China" scope refers to the global market outside China. Altimeter Capital's forecast comes from founder Brad Gerstner's public statements at the All-In Summit in September 2026.
Core Data
Table 1: New Global Data Center IT Capacity (excl. mainland China)
| Year | New capacity (GW) |
|---|---|
| 2025 | 15.6 |
| 2026 | 25.0 |
| 2027 (forecast) | 51.2 |
Table 2: Construction Progress Evidence for 2027
| Metric | Value |
|---|---|
| Campuses in late-stage construction | About 40 |
| Total capacity in late-stage construction | Over 24.3 GW |
| Progress of most campuses | More than half complete |
Table 3: Leases and Demand Scale (2026)
| Metric | Value |
|---|---|
| Leases signed in 2026 YTD | Slightly below $1 trillion |
| Oracle leases in H2 2025 | About 4.5 GW |
| Organizations seeking gigawatt-scale leases | Meta, AWS, Microsoft, Google, NVIDIA, AMD, Anthropic, OpenAI |
Table 4: Modular Build Efficiency Gains
| Metric | Before | After |
|---|---|---|
| 50 MW AI data hall delivery cycle | 22 months | 14 months |
| DayOne delivery cycle | Over 18 months | 9 months |
| On-site labor | Baseline | Down up to 63% |
Table 5: Behind-the-Meter Power
| Metric | Value |
|---|---|
| Reservations in early 2024 | Near zero |
| Reservations in August 2026 | 75 GW |
| Equipment suppliers | 22 |
Table 6: 2027 Forecast Divergence (model comparison)
| model | 2027 new capacity forecast (excl. mainland China) | Release time |
|---|---|---|
| SemiAnalysis | About 51.2 GW | October 2026 |
| Altimeter Capital (Brad Gerstner) | Close to 25 GW | September 2026 |
Table 7: Geographic Distribution (excl. mainland China)
| Region | 2026 (GW) | 2027 forecast (GW) |
|---|---|---|
| Non-U.S. regions | 6.9 | 13.2 |
| Global total | 25.0 | 51.2 |
Field Notes
- New capacity: Data center IT capacity newly delivered in the year, in GW; 1 GW approximates one large AI data campus.
- Late-stage construction: Campuses entering mechanical/electrical installation and commissioning, mostly more than half complete.
- Lease value: Value of binding, non-cancellable data center lease contracts.
- Behind-the-meter power: Generation that supplies data centers directly without going through public grid dispatch.
- Forecast divergence: Difference among institutions on actual 2027 delivery; SemiAnalysis at 51.2 GW, Altimeter Capital near 25 GW.
Data Sources
- SemiAnalysis "Datacenters 2027: The Year of Acceleration" (published October 2026)
- Xinzhi Times via Sina Finance: 51.2 GW forecast for 2027 global AI capacity (October 25, 2026) link