Don’t discard the mainframe just yet… it’s hard to come by unbiased opinions in this question, but – are there any major banks running the backbone of their operations on non-mainframe systems?
Mainframe shops that invest in getting current with operating systems and software can run mainframes at lower cost than those that don’t. Investing in legacy is, and can be, a competitive advantage. Is legacy always better than new application build-out on new hardware systems? Certainly not. But neither is migrating to the newest cool shiny thing a guarantee of lower cost of management and operations. Mainframe shops running current hardware and software can take advantage of lower cost subsystems for running Linux, data and Java workloads for example.
via The Lesson of RBS: Invest in legacy, Invest in the mainframe.