Life in a city made of computers

Here's a transcript of a classic Charles Strossian rant, his speech at TNG's Big Tech Day in Munich last June. Entitled "How low (power) can you go?" it's a look at life in a city whose entire surface was made of sensing, computing smart matter:

I also noted that the combined video and audio streams from the entire population of Germany, over a period of a century, would occupy on the order of a hundred kilograms of Memory Diamond — a hypothetical crystalline form of carbon used for data storage, in which each bit is represented positionally by an atom of one isotope or another (in this case, carbon-12 or carbon-13). With Avogardro's number of bits storable in 12.5 grams of carbon, if we can figure out how to read and write this stuff we can store roughly 0.5 petabytes in each gram of substrate.

(Using this yardstick, on a world-wide scale Google currently processes about 2 grams of data per hour.)

So, the first point to note is that if the world of 2032 has this level of ambient computing power at all, we're likely to have the data storage to go with it.

Let's assume we have found a use for our billion cpu city, and we're running a billion operations per second on each cpu. If each operation generates one byte of useful output — from air quality sensors, or cameras, or whatever — then our city is producing 1018 bytes of data per second. That's heavy data: that's 2000 grams per second. We're really going to have to get our data de-duplication strategies under control, lest we build up memory diamond landfill at a rate of seven tons per hour! Luckily most computer programs don't generate anything like one byte of output per operation — that's a ridiculous edge condition. Given the bandwidth and power constraints on our tiny solar powered processors, I'd be surprised if they averaged even a megabit per second of output — and even that would correspond to uncompressed high-definition video from every square metre of our city. So let's arbitrarily hack six orders of magnitude off that peak data output figure. Our city of 2032 is emitting as much information in a second as Google processes in an hour today: remarkable, but not outrageous in context.

How low (power) can you go?