[fomb]

I have many apps on Heroku, all running Rails, and mostly running on Unicorn, with three or four workers. Most of the apps I've seen pass me by use no more than 150Mb per worker, and there's a fair amount of work going on in many of them with image processing and the like.

512Mb for a single application sounds incredibly high to me.

EDIT: After looking at the docs, it seems like 512Mb isn't even a hard limit: https://devcenter.heroku.com/articles/dynos#memory-behavior