If you know what you're doing you will not pass around huge arrays (in PHP) by value. Or pass them around (in CakePHP) at all, it's maybe a MVC warning flag that you do something in a place you shouldn't.

Related note: CakePHP 3.0 (current is 2.x) will use objects [1].

[1] https://groups.google.com/d/msg/cake-php/-TLn6RpHt4U/EAP0lt2...