Nvidia’s AI chips have more than doubled in price on China’s black market as a US crackdown on illicit exports collides with strong demand from Chinese companies.The price of the US tech giant’s flagship DGX B300 server has soared to more than Rmb8mn ($1.1mn) over the past six months, up from Rmb4mn, according to FT interviews with multiple Chinese chip traders. The system, which contains eight Blackwell graphics processing units, typically retails in the US at about $400,000.Nvidia’s RTX 6000 P...