NVIDIA · Blackwell Ultra
NVIDIA GB300 NVL72
Blackwell Ultra rack-scale system: 72 GPUs and 36 Grace CPUs in one liquid-cooled NVLink rack, with a published enterprise reference architecture.
Rack-scale specification
- GPU count
- 72
- GPU
- NVIDIA Blackwell Ultra GPU
- CPU count
- 36
- CPU
- NVIDIA Grace CPU
- Cooling architecture
- Direct-to-chip liquid cooled (rack-scale)
- Rack architecture
- NVL72 — 72-GPU NVLink domain, single rack
- Networking family
- NVIDIA Quantum-X800 InfiniBand or Spectrum-X Ethernet + BlueField-3 / ConnectX-8
- Last updated
- 2026-08
Cooling options
- Direct liquid coolingREFERENCE ARCHITECTURE
Primary published architecture. Facility water loop, CDU capacity and manifold/QD selection follow the rack requirement.
- Hybrid liquid + airSUPPORTED OPTION
Additional residual air-cooling infrastructure is required for the non-liquid share of rack heat. Confirm residual kW with the provider.
- Air coolingNOT APPROPRIATE BASED ON AVAILABLE DATA
Not documented as a facility option for this rack platform.
Approximate module sizing
| Module | Design rack power | Approx. racks | Basis |
|---|---|---|---|
| 2.5 MW | 142 kW | 18 | Design calculation, not a guaranteed physical rack count |
| 5 MW | 142 kW | 36 | Design calculation, not a guaranteed physical rack count |
| 10 MW | 142 kW | 71 | Design calculation, not a guaranteed physical rack count |
| 20 MW | 142 kW | 141 | Design calculation, not a guaranteed physical rack count |
Facility power requirement
Up to 142 kW per rack (full rack electrical requirement)
OFFICIAL NVIDIA SOURCE · SOURCE QUALITY HIGH
Source: NVIDIA Enterprise Reference Architecture — GB300 NVL72
Document: NVIDIA Enterprise Reference Architecture — GB300 NVL72
Source date: 2026-06
What this determines
- Rack is liquid cooled — CDU, manifold, QD and cold-plate loop packages auto-added.
- Rack facility power taken from the official reference architecture, not user guesswork.
- Networking infrastructure sized for rack-scale NVLink + scale-out fabric.