There is a thing left over from the 90s that may still raise its fuzzy little head from time to time and I wondered about it the other day when I was asked if we had an UPS. My first experience with the uninterruptible power supply concept was found in the dark in the Navy's Battle Lanterns of great and unforgiving darkness. When a ship loses power unexpectedly it gets very very dark and so they have these lanterns that automatically energize when the circuit feeding them power dies. They have batteries in them and there is a preventive maintenance check to ensure the lights are tested routinely and batteries replaced as required. What one usually finds in the less visited places on a ship is that when the power goes away the lights do not come on.
So we had the UPS back in the day to give our sailors just enough time to safely power down the surveillance systems so they did not suffer any damage due to a sudden unplanned loss of power. We stressed in training that it was just enough time to shut the damned thing down and not to mess around if we wanted the systems to restore properly when the power came back. You can guess how that played out in the event.
I was wondering though, after Fukushima and other disasters, what does the UPS look like for a huge Data Center or an AI? There was a wonderful description of the death of the last AI in The Postman. I thought it was one of his better books but then I liked all of his books except for everything after Earth. I imagine a Data Center UPS would be about the size of New Hampshire and provide enough power for about 5 minutes. I'm thinking the AI is doomed.
1 comment:
Having been the lead network engineer for a multinational company, I had the opportunity to work with our own as well as several large hosting facilities that were 99.999% uptime. The way we did it was N+1 generators and 90 minutes of full load batteries. N+1 is where N is the number of generators required to fully power the facility. The plus one was for fault tolerance. In our case, one would work so we had another as a backup. They were tested weekly and serviced quarterly. The batteries were tested enough with our brown outs and short blackouts before the generators kicked on. The biggest problem was cooling. Even in winter we had to run the air handlers to keep all that gear cool. Larger facilities such as major AI facilities most assuredly have multiple utility providers with their own local substations and transformers to help with the need for a lot of batteries but they would still have banks of the biggest generators.
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