The Blackwell graphics processing units overheat when connected together in server racks designed to hold up to 72 chips, the report said, citing sources familiar with the issue. The chipmaker has asked its suppliers to change the design of the racks several times to resolve overheating problems, according to Nvidia employees who have been working on the issue, as well as customers and suppliers with knowledge of the issue, the report said without naming the suppliers. In March, Nvidia unveiled Blackwell chips and had earlier said they would ship in the second quarter before encountering delays, potentially affecting customers such as Meta Platforms, Alphabet's Google and Microsoft.