In a repurposed Electrolux factory in Memphis, xAI trained Grok 3 on a supercomputer dubbed “Colossus,” which the company says includes 200,000 Nvidia H100 GPUs. Elon Musk and senior xAI employees described Grok 3 as “the smartest AI on Earth” in a recent livestream, citing each GPU’s capacity of up to 4 PFLOPS (four quadrillion…