800 VDC is the datacenter inflection point: 120kW racks need ~2,500A at 48 volts
BenBajarin · x · 2026-09-18
Analyst Ben Bajarin reiterates his March 800 VDC thesis: modular datacenters are coming, and 800-volt DC is the likely architectural destination for AI power delivery — with NVIDIA's platform roadmap setting the pace.
- AI rack density keeps climbing, from legacy 10–20kW racks to 120–300+kW accelerated racks; the AC-distribution/low-voltage chain was never designed for this.
- Physically, delivering 120kW at 48V requires 2,500A: oversized copper, more conversion stages, more waste heat and cooling burden.
- 800V cuts required current 16x, reduces conversion losses, shrinks cabling and busbars, and improves the share of site power becoming useful AI work.
- The real debate is structural: how much more rack-level compute the electrical plant can absorb; the market still underappreciates the transition.
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