NVIDIA plans to expand its tightly connected GPU systems from 72 to 576 by 2027, pushing in-rack copper links to their physical limits due to attenuation, power, and heat. The NVLink Fusion ecosystem now includes photonics companies like Ayar Labs and Lightmatter, developing optical chiplets and photonic interposers respectively. Industry participants anticipate high-volume optical scale-up implementations around 2028, with packaging and measurement/testing identified as critical bottlenecks for manufacturability.
The physical limits of copper for in-rack GPU links are accelerating the shift to optical solutions, making advanced packaging and testing critical chokepoints for future compute scaling.