MacOS El Capitan requires at least 2 GB of RAM will run on:
- Macbook Unibody and regular Macbook: Late 2008 - 2010 (no models after 2010)
- MacBook Pro: Early 2008 - 2013 (after 2014 you'll need a SSD)
- Mac Mini: Early 2009 - Late 2014 (after 2014 they're soldered in)