“It is the most advanced ai accelerator in the industry,” boasted Lisa Su, boss of Advanced Micro Devices (amd), at the launch in December of its new mi300 chip. Ms Su rattled off a series of technical specifications: 153bn transistors, 192 gigabytes of memory and 5.3 terabytes per second of memory bandwidth. That is, respectively, about 2, 2.4 and 1.6 times more than the h100, the top-of-the-line artificial-intelligence chip made by Nvidia.