Today at TechCrunch Disrupt 2020, leaders from three quantum computing startups joined TechCrunch editor Frederic Lardinois to discuss the future of the technology. IonQ CEO and president Peter Chapman suggested we could be as little as five years away from a desktop quantum computer, but not everyone agreed on that optimistic timeline.

“I think within the next several years, five years or so, you’ll start to see [desktop quantum machines]. Our goal is to get to a rack-mounted quantum computer,” Chapman said.

But that seemed a tad optimistic to Alan Baratz, CEO at D-Wave Systems. He says that when it comes to developing the super-conducting technology that his company is building, it requires a special kind of rather large quantum refrigeration unit called a dilution fridge, and that unit would make a five-year goal of having a desktop quantum PC highly unlikely.