we actually do lots of background ocr and only need a few "small" web machines 2cores 4gig totally enough (3 of them for ha) and the ocr processing takes like 8 cpu's 32gig to be "fast" and we need to spin up 2 or 3 additional machines between 9 and 18 o clock this is way way cheaper in the cloud, especially if you need "infinity" storage (without too much hurdles) (especially storage is still a hard problem)