Silicon Valley’s artificial intelligence frenzy has found a new gear.

Two and a half years after OpenAI set off the artificial intelligence race with the release of the chatbot ChatGPT, tech companies are accelerating their A.I. spending, pumping hundreds of billions of dollars into their frantic effort to create systems that can mimic or even exceed the abilities of the human brain.

The tech industry’s giants are building data centers that can cost more than $100 billion and will consume more electricity than a million American homes. Salaries for A.I. experts are jumping as Meta offers signing bonuses to A.I. researchers that top $100 million.

And venture capitalists are dialing up their spending. U.S. investment in A.I. companies rose to $65 billion in the first quarter, up 33 percent from the previous quarter and up 550 percent from the quarter before ChatGPT came out in 2022, according to data from PitchBook, which tracks the industry.

“Everyone is deeply afraid of being left behind,” said Chris V. Nicholson, an investor with the venture capital firm Page One Ventures who focuses on A.I. technologies.

This astonishing spending, critics argue, comes with a huge risk. A.I. is arguably more expensive than anything the tech industry has tried to build, and there is no guarantee it will live up to its potential. But the bigger risk, many executives believe, is not spending enough to keep pace with rivals.

“The thinking from the big C.E.O.s is that they can’t afford to be wrong by doing too little, but they can afford to be wrong by doing too much,” said Jordan Jacobs, a partner with the venture capital firm Radical Ventures.