Smartphone shipments are growing at a rate of 40 percent annually, and various forecasts predict that in four years there will be 1 to 2.6 billion smartphones, which will far outnumber PC shipments. But per-user infrastructure costs are not moving in concert with this dramatic revenue drop. In particular the back-end data center continues to operate as if it is still the halcyon days of ever-growing ad revenues. Because of this, a new generation of mobile-centric data centers will arise over the next three years, with chips, servers, and power architectures customized for mobile workloads. Here’s what tomorrow’s data center will look like.