¹DISCLAIMER: This is an IBM internal study designed to replicate a typical IBM customer workload usage in the marketplace. Results may vary. The workloads consisted of an airline flight reservation system (running MongoDB and node.js) and a transactional core banking application (running WAS and Db2). Four instances of the airline system were run, one instance simulating a Dev/QA environment, and three instances simulating a Production environment. The total number of IBM Z cores needed to deliver the workloads was 28.Both the x86 and z15 environments had access to the same storage array. Total Cost of Ownership is defined here to include hardware, software, labor, networking, floor space and energy costs over a period of 5 years. IBM internal hardware list prices were used. x86 server prices were acquired from IDC. IBM software pricing was standard list prices with 20% discount applied. For more details contact the IT Economics team at IBM.