I've got some experience with a big academic data center - >1 acre floor space, >10MW, ~$100M construction cost. I've also worked for commercial companies of va

I've got some experience with a big academic data center - >1 acre floor space, >10MW, ~$100M construction cost. I've also worked for commercial companies of various sizes. If your compute installation is big enough that payroll is a small fraction of the operating cost, then it's way cheaper than cloud. (that payroll has to include people who actually know how to build and run a huge compute installation) The problem is that people come in integer units, you need a bunch of them to cover a bunch of different areas of expertise, and the particular ones you need are expensive. If you've got $1M worth of computers, you're almost certainly better off scrapping them and going to cloud, although the folks you're currently paying to run them might disagree. If you have $100M+ worth of machines it's a whole different ballgame; I'm not sure where the exact crossover is. Note - that's assuming a single data center, and that you're big enough to build your own data center instead of renting colo space. If you need your machines to be geographically dispersed, you'll need to be even bigger before it's cheaper than cloud, and I'm not sure whether you'll ever hit crossover if you're renting colo space.