About 25 years ago at work we had a Lab/Test Berth which had a big old computer in it. The air conditioning was badly set up and when the lab was unoccupied overnight and weekends is got uncomfortably cold when the lab technician came to work in the morning. So he began to leave the computer turned on all the time functioning as a room heater, which was contrary to our operating procedures.
We soon discovered that this particular computer was far more reliable than similar ones used elsewhere. That's how we learned that continuous operation is more reliable than ON/OFF operation (at least for this type of computer).
