Together AI, one of several up-and-coming cloud providers renting out Nvidia chip servers to AI developers, is in talks with investors to raise around $1 billion in funding at a $7.5 billion valuation before the investment, according to two people with knowledge of the fundraise. The funding would more than double its valuation from a year ago and could boost Nvidia’s efforts to diversify its base of customers as investors worry about the chip designer’s dependence on a few large, traditional cloud providers.