Why Andy Bechtolsheim Says 800V DC Needs Solid-State Circuit Breakers
At the 2026 OCP Global Summit in San Jose, Andy Bechtolsheim gave a talk on how AI data centers should be built. Andy co-founded Sun Microsystems and Arista Networks. He has spent his career designing the machines that run the internet.
His big idea fits in three words: Small is Beautiful.
Pack the same computing power into about one-tenth of the space. But it only works if the power inside is delivered and protected in a new way.
This post covers the power problem Andy laid out, the solution he proposed, and why solid-state circuit breakers like our Atom Switch sit at the center of it.
The problem: AI racks are outgrowing today's power
"It takes at least 24 months to build a Gigawatt scale AI Datacenter."
The longest part of that build is the mechanical and electrical work. Andy said on-site labor for that work is now what holds most projects back.
Today's sites also aren't built for what's coming. The biggest ones, like xAI Colossus and Meta's Hyperion, were built for 120 kW racks. The racks coming next need far more power than that. Then there's how the power gets to the racks. Andy showed that in a typical 480V AC system, only about 93% of the power makes it from the grid to the chips. For a 1 GW data center, that's about 70 MW lost.
More power in every rack also means more energy behind every fault. The parts that keep that power safe have to keep up.
His solution: a next-gen AI data center powered by 800V DC
"Next generation AI Datacenters can increase power density up to 10X."
Andy laid out a design he calls his "next-gen AI data center." It's about 10 times denser than the AI data centers being built today. Meta's Hyperion Phase 2 plans 5 GW in 10 million square feet. His design fits the same 5 GW into 1 million.
To power it, he takes grid power straight down to 800 volts of DC. He showed this is about 3% more efficient than today's 480V AC, or 30 MW saved per gigawatt.
He also built the power design so one failure doesn't take a rack down. The design is made of repeatable blocks he calls pods. Each pod gets four 9.6 MW power paths, each with its own transformer, battery backup and breakers. That's one more path than the pod needs, which engineers call N+1. Andy said this N+1 setup holds all the way from the grid to the chip.
But DC power behaves differently from AC when something goes wrong. That's where Andy's talk turned to breakers.
Why 800V DC needs solid-state breakers like our Atom Switch
"Arc Flash is a Lethal Threat."
Andy gave solid-state circuit breakers their own part of the talk, and he started with the danger they protect against.
What a fault is
A fault happens when electricity finds a shortcut it shouldn't take. A cracked cable, a failed part or a loose connection can let current skip the load and rush straight through. With almost nothing in its way, the current climbs far above normal in a fraction of a second. If nothing stops it, it can melt metal, start a fire or jump through the air as an arc flash. That's the lethal threat on his slide.
Why faults are harder to stop at 800V DC
In Andy's design, each 2.4 MW circuit carries 3,000 amps at 800 volts, with battery backup sitting right on the DC side. A fault on a circuit like that has a lot of energy behind it, and batteries can push current into a fault the instant it happens.
There's also a lot to protect. A 921.6 MW site built from 32 of his pods holds more than 1,000 GPU racks. Each rack is fed by four 800V circuits, and every one of those circuits needs protection that works every time.
Then there's DC itself. AC power crosses zero many times a second, and a regular breaker uses that moment to put out the arc. DC never crosses zero. The arc keeps burning until the breaker's contacts pull far enough apart to break it.
Why regular breakers fall short
Andy listed three reasons conventional protection can't keep up with 800V DC:
They take tens of milliseconds to clear a fault.
DC has no zero crossing to help put out the arc.
Even fast fuses aren't fast enough.
What solid-state circuit breakers solve
A solid-state circuit breaker has no contacts to pull apart. It cuts the power with a semiconductor switch. To show what one looks like, Andy put our Atom Switch on screen next to five points. Here's what each one solves:
Clears a fault in under 10 microseconds. A millisecond is 1,000 microseconds, so the fault is stopped before the current has time to climb.
Arc-free operation. Nothing pulls apart, so no arc forms. The zero-crossing problem goes away.
No moving parts. Nothing wears out from tripping again and again.
Fully digitally controlled. The breaker is run by electronics, not springs and magnets.
"Safe by design." Safety comes from how the breaker works, not from protective gear added afterward.
That's why he made solid-state circuit breakers one of his five building blocks. In his design, a 250A solid-state breaker protects every 800V circuit that feeds a rack. That's 200 kW per circuit. Racks with more power will need bigger ones, like 400A.
This is the problem we built our breakers to solve. At the summit, we showed our latest RPP with 250A solid-state circuit breakers. If you're planning power for a high-density AI data center, let's talk.