Cloud providers want to crank up rack power 10X for AI

  • Cloud providers are looking to ramp up rack power to as much as 1 megawatt
  • This kind of power level is still several years out
  • Key hurdles include worker safety and the physical space available in data centers

The electrical infrastructure in data centers has remained static for a long time, but change is on the horizon. An executive from data center supplier Flex told Fierce that hyperscalers and cloud companies are looking to drastically increase rack power levels in response to demand for higher density compute for artificial intelligence (AI).

How much higher? “We’re literally talking to people that want to take racks not to 200 kilowatts; we’re talking to people about how do we get to 1 megawatt,” Chris Butler, president of Flex’s embedded and critical power businesses, said.

Rack power levels today generally run around 15 kilowatts or less, though AI is poised to drive the power range to 40 to 100 kilowatts in the near future. But 1 megawatt would put rack power at 10 times the upper limit of that range.

“If you get to that level of density, you really need to bring that power directly into the rack, or you can’t do it efficiently,” Butler said. Why? Because there’s already a massive amount of loss — in the realm of 20 to 30% — that occurs when data center operators try to convert power levels down from the 48 volts that comes in from the grid to the 0.8 volts that a rack needs.

“I’m a big believer that if we can bring power into the rack at a much higher level than what it sits at today, you can reduce those conversion losses,” he said.

When might we see these uber-racks in the wild? Not for another couple years at least, Butler said. Think 2027 or 2028 at the earliest. Interestingly, that’s around the same time we could start seeing chips in the 3,000-watt range.

Dell’Oro Group has forecast that the data center physical infrastructure market — which includes power and thermal management gear rather than IT gear — will grow to at a compound annual growth rate of 13% to hit $50 billion by 2028. Power distribution is expected to be one of the fastest-growing segments.

Hurdles to higher power

If you’ve been paying attention, you know data center operators have already run up against the limits of what the power grid can supply. Strangely, though, Butler said that hasn’t come up as a hurdle in his discussions with cloud players.

Instead, he said, they are operating under the assumption that the power supply is infinite and that any short-term problems will be resolved by yet-to-be-determined solutions — perhaps natural gas or nuclear power sources or more efficient cooling methods.

“You can solve this problem from multiple different angles, and I think that’s one of the reasons why everybody is like ‘let’s continue our efforts,’” he said. “I haven’t seen that creep into the decision-making process as a barrier.

So, if not power, what is a hurdle to higher rack power? Perhaps surprisingly, it’s worker safety.

Butler said regulations prevent employees from working on gear above certain power levels without additional precautions or special training. Additionally, the physical layout of racks presents a problem, Butler said.

“The way data centers are constructed today, you have vertical racks that are a specific width and depth that is pretty standard across the industry,” he explained. “So, when you start bringing more power to the rack, the rack is probably going to get deeper.”  There will also likely be a need to isolate higher voltage racks from lower power IT gear, Butler added.

“People are having those conversations today. We weren’t having those conversations two or three years ago,” he concluded. “AI is causing everybody to rewrite the book.”