I think this is still IBMs license model (at least a few years ago). It was explained to me you basically license a certain amount of compute even though the ha

I think this is still IBMs license model (at least a few years ago). It was explained to me you basically license a certain amount of compute even though the hardware is in your data center and you pay overages if you exceed your licensed throughput. Since you license a fixed amount, there were projects at the company looking at running batch/non time sensitive jobs on the mainframe since it was effectively free off peak (I guess power cost was trivially compared to licensing).