SITUATION EXPLAINED: The race is now for the most power-efficient inference chip. • Nvidia's Groq 3 LPX rack is now in full production, with Nebius the first AI cloud to adopt it, online before the end of the year • It's liquid-cooled with 256 LPUs and slots into the Vera Rubin platform • Paired with an NVL72, Nvidia claims up to 35x higher inference throughput per megawatt on trillion-parameter models • It comes from a $20 billion licensing deal signed on Christmas Eve, Nvidia's largest ever,…