[jrochkind1]

> It doesn't matter if you think one dyno per request is "bullshit" or not, Rails isn't multithreaded

Sure it is. You just have to set `config.threadsafe!`, which right now is slated to be on by default in rails4.

But then you need a server stack that supports multi-threaded requests, such as puma which the parent comment mentioned using.

And then if you're using MRI, your multiple threads in a process still can't use more than one cpu at a time -- but this _probably_ doesn't matter in the scenario we're talking about, because a single heroku dyno isn't going to have access to more than one cpu at a time anyway, right?

How this all shakes out is indeed confusing. I am _not_ saying "If you just use puma and config.threadsafe!" all is well with their scheduler. I do not know one way or the other, it is hella confusing.

But it is incorrect to say "Rails isn't multithreaded, so what do you propose they do"