ATCA (Advanced Telecommunications Computing Architecture) was originally developed for carrier grade communications, but has since expanded to other applications like high performance computing. In a typical configuration, an ATCA shelf is 12U high with a 1U high power supply rack mounted at the bottom.

https://www.youtube.com/watch?v=rfXG0oNmvUE

The HFE series of hot-swap, plug-in power supplies was developed by TDK-Lambda for a wide range of applications, including computing. The 48V output 2500W HFE modules were picked to power a new ATCA system, offering up to 10,000W in a 1U rack because of product reliability. Technical support was also provided to the customer as they required a PMBus™ communications interface for remote programming and monitoring.