per Rubin Ultra Kyber rack (NVL144) on 800 VDC
~600 kWforecastcontested
| Value kind | forecast — Forecasts are time-bound outlooks, not specifications; test decisions across plausible scenarios. |
|---|---|
| Caveat | NVIDIA's published figure (GTC 2025) is 600 kW per Rubin Ultra Kyber rack, and GTC 2026 did not revise it. NVIDIA targets H2 2027. SemiAnalysis reported in July 2026 that Kyber NVL144 slips to 2028 on PCB-midplane manufacturability; NVIDIA says its roadmap is intact but has not published a revised date. SemiAnalysis (26 May 2026) also puts Kyber Ultra at 'approaching 660 kW', a single-analyst estimate noted here but not adopted. On 30 June 2026 SemiAnalysis reported Rubin Ultra with two compute dies rather than the four first expected. NVIDIA has not confirmed that package, and no new rack power follows from it. |
| As of | H2 2027 roadmap (GTC 2025); 2028 reported July 2026 |
| Source | NVIDIA GTC (Jensen Huang); DCD, Tom's Hardware |
| Review | checking…review by 2027-03-31 · standard cadence |
| Recorded changes | last 2026-10-05 · 2 revisions tracked |
| Claim id | per-rubin-ultra-kyber-rack-nvl144-on-800-vdc |
Where the guide uses it
- 0.2 How to Read This Guide: Decisions, Consequences & Reference Data
- 1.1 The Archetype Decision Framework: Workload Is the Master Variable
- 1.2 Training Data Centers: Synchronous, Dense, Checkpointable
- 4.6 LV Distribution: Busway, PDUs, RPPs & Rack Power
- 4.7 The DC Power Revolution: 48V → ±400V → 800V & Disaggregated Sidecar Power
- 5.1 Thermal Fundamentals & the Density Wall
- 6.1 Building Typologies & Data-Hall Layout
- 7.2 NVIDIA Accelerators: Hopper → Blackwell → Vera Rubin → Rubin Ultra → Feynman
- 7.13 The Rack as Integration Unit
- 13.3 Electrical Power Acceptance (L3/L4)
- B Reference Designs & Worked Examples
← Full numbers register — every date-stamped figure in the guide, with revision history.