"Don't use ORMs"? I'm sorry, that's just plain wrong, or you were exposed to the wrong ORMs. Doctrine2 has great scalability - it has all sorts of caching built into it - result caching, query caching, and so on and so forth. It's actually -way- more scalable, and easier to develop for, than writing raw SQL (which, by the way, is a portability nightmare).
Also, if you want to use a decent MVC framework, not using an ORM would be quite dumb.
And if you're not using a good, modern, scalable MVC framework in this day and age, well, I pray for your soul.
So, USE AN ORM!!!