The company, valued at $5 billion, plans to use the funds to hire top talent and acquire computing power, with investors including Andreessen Horowitz, Sequoia Capital, and DST Global.
Sutskever, 37, is one of the most influential technologists in AI. He co-founded SSI in June with Gross, who previously led AI initiatives at Apple, and Daniel Levy, a former OpenAI researcher.
Sutskever is the chief scientist, Levy is the principal scientist, and Gross is responsible for computing power and fundraising. Sutskever said his new venture made sense because he "identified a mountain that's a bit different from what I was working on."
SSI is currently very much focused on hiring people who will fit in with its culture. Gross said they spend hours vetting candidates to see if they have "good character" and are looking for people with extraordinary capabilities rather than overemphasising credentials and experience in the field.
"One thing that excites us is when you find people that are interested in the work, that are not interested in the scene, in the hype," he added.
SSI says it plans to partner with cloud providers and chip companies to fund its computing power needs but hasn't yet decided which firms it will work with. AI startups often work with companies such as Microsoft and Nvidia to address their infrastructure needs.
Sutskever was an early advocate of scaling, a hypothesis that AI models would improve in performance given vast amounts of computing power. The idea and its execution kicked off a wave of AI investment in chips, data centres and energy, laying the groundwork for generative AI advances like ChatGPT.
Sutskever said he would approach scaling in a different way than his former employer, without sharing details.
"Everyone just says scaling hypothesis. Everyone neglects to ask, what are we scaling?" he said.
"Some people can work long hours, and they'll just go down the same path faster. It's not so much our style. But if you do something different, then it becomes possible for you to do something special."