Today, the Green IT Cube at GSI Darmstadt was inaugurated. This building has six floors, each of them designed for housing server racks with up to 2 MW (that's roughly 1000-2000 GPU compute nodes) of power usage. That's a total of 12 MW on a surface area of only 900m². The energy overhead for the cooling systems in the commissioning tests were only 2%, with a theoretical maximum overhead of 7%. That's waayy better than the current average of 80% overhead.
This building is a huge step for energy efficient high performance computing. Best of all: I'm working on enabling the physicists, who are writing the software to run on those machines, to write code that runs efficiently on modern hardware. We are not tackling the issue of Green IT from one side, but from every possible angle.