I’ve never worked with major enterprise or government systems where there’s aging mainframes — the type that get parodied for running COBOL. So, I’m completely ignorant, although fascinated. Are they power hogs? Are they wildly cheap to run? Are they even run as they were back in the day?
Modern systems do a lot more work per second than these old machines, while drawing less power. If you were to collect a large enough collection of mainframes to equal the performance of a modern rack server, you would need 10-1000 times the power to run the old stuff, depending on how far back you want to go - even 10 year old hardware can cost 4-10 times more in electric bill compared to a modern server with the same total performance level.