What it's like inside the data centers powering the AI boom

Behind the scenes: I recently toured an innovation lab by Digital Realty in Northern Virginia, home to the world's largest concentration of data centers.

• Digital Realty is one of the world's oldest and most established data center operators.
• The lab, which opened in September, allows the company to test new technologies and show visitors — like customers, lawmakers and journalists — what it's like to be inside.
• A similar one opened in London in June.

Inside the room: I was immediately hit with what I can only describe as "demented white noise."

• The sound comes from fans cooling racks of AI chips that generate enormous amounts of heat.
• It felt like standing inside one giant computer. Even beneath my feet, a glass floor revealed pipes and other infrastructure helping keep the servers cool.

Zoom in: At the bottom of one of the closet-sized racks sat a gold-colored Nvidia AI system packed with multiple AI chips.

• The gold is intentional — but not real. "Gold is associated with high value and performance," Nvidia spokesperson Kira Sarkisian said by email.
• "That's about $1 million right there," said my tour guide, Digital Realty engineer Tor Nyström, referring to the entire rack.

Reality check: Getting inside a data center is not easy.

• Some companies flatly declined my request for a tour, while others require signing a non-disclosure agreement to get inside the walls of a campus (server halls are typically off-limits altogether).

Friction point: This type of secrecy is part of what's fueling the backlash against data centers, alongside strains on electricity and local water supplies.

My thought bubble: Digital Realty let me photograph its innovation lab and tour a nearby campus under construction. I came away convinced companies can show the public how these facilities work without revealing proprietary information.

The big picture: AI feels invisible. It isn't. It's racks of servers, cables, cooling systems and enormous amounts of electricity — and sometimes water.

• Compared with an offshore wind farm or an underground coal mine, it's remarkably uneventful. That's by design.
• If excitement is happening inside a data center, something has probably gone wrong.

Zoom out: After the tour of the test server hall, we drove a few miles to what Digital Realty calls its Digital Dulles campus, which could eventually include 13 data centers with an investment north of $10 billion over the next decade.

State of play: The most notable parts of a data center are also the most controversial: the infrastructure needed to power and cool AI. Otherwise, from the outside, data centers look like massive, windowless warehouses.

• Multiple electricity substations are visible, along with whatever cooling technology is used, which includes either huge water-filled cooling tours or rows of dozens of industrial air conditioners that require large amounts of power.
• Although plans are still being finalized, Digital Realty anticipates these data centers will use a type of cooling that relies more on energy than water.
• This means no huge cooling towers were on site, which would be easily visible at those that do use water-based cooling.

Stunning stat: I counted almost 40 diesel generators hooked up to one data center building.

• Digital Realty spokesman Kevin Gundersen said those are only used for backup power purposes and occasional testing, so they aren't on most of the time.
• Normally, the campus draws power from the broader electricity grid. In Virginia, that's largely natural gas and nuclear power.

What's next: In a sign of the AI's global footprint, Digital Realty is eyeing at least three more locations for new innovation labs: Singapore, São Paulo, Brazil and Johannesburg, South Africa.