Andreessen Horowitz has closed a $1.1 billion Machine Age Fund, its first vehicle dedicated exclusively to AI hardware and physical infrastructure. The fund will invest across computer chips, memory, interconnects, data centers, robots, edge devices, cooling systems, materials, electrical capacity and real estate needed to support large-scale AI. It is co-led by managing partner Raghu Raghuram and general partner Martin Casado and sits alongside rather than within a16z's existing fund family. The launch reflects mounting physical constraints as AI scales. Compute density in AI racks has jumped 28 times from NVIDIA's H100 to its Rubin architecture, while power draw has surged from a historical 5 to 10 kilowatts per standard rack to 100 to 250 kW for current AI-optimized racks, with projections that individual racks could reach 1 megawatt within three years. Modern AI workloads are increasingly memory-bound rather than compute-bound, elevating memory architecture, high-speed interconnects, storage and data-center design as critical bottlenecks. Hardware already accounts for more than 20% of a16z's recent deal flow. The firm framed the push as opening the throttle on AI's physical buildout and described advancing AI as a social and national imperative. For capital-intensive chip designers, data-center developers and robotics startups that have traditionally struggled to attract venture backing, the vehicle adds a dedicated capital source as constraints shift from software to silicon, power and physical space.