HANGZHOU, Sept. 23 -- The chip Alibaba unveiled at its annual Apsara Cloud Conference on Monday has a name drawn from ancient mythology - Zhenwu, the dark warrior - and specifications that arrive as a direct answer to a question American policymakers have avoided for three years: what happens when export controls on advanced semiconductors are comprehensive enough to force China's most capable companies to build their own?

T-Head, Alibaba's chip design subsidiary, presented the Zhenwu V900 AI accelerator in Hangzhou, the eastern coastal city where the company was founded. Chief executive Eddie Wu described it as "the most powerful AI chip in China today." The V900 delivers three times the performance of its predecessor, the Zhenwu M890, ...