This paper explores the evolution of data center cooling technology to address the anticipated demand for increased rack density for IT equipment in the white space. In our experience, most of the hyperscale data center operators have reached a density limit for IT equipment, due to the inherent limitations of air-cooled cabinets. On average, much of the industry is achieving rack density as high as 11 kW/cabinet with current designs. The emergence of artificial intelligence processing requirements and further density increases for cloud computing will continue to push that limit. We anticipate that many data centers will require significantly higher density moving forward, with some systems requiring as much as 40 kW/cabinet in the near future.