It depends on IBMs sales target. Some customer may change it even every 3-5 years, but most i saw were between 5 and 7. Energy and data centre floor space are

It depends on IBMs sales target. Some customer may change it even every 3-5 years, but most i saw were between 5 and 7. Energy and data centre floor space are not a real thing here, the mainframe usage of physical resource is nothing compared to other systems.