I am considering Smarty as my web app templating solution, and I am now concerned with its performance against plain PHP.
The Smarty site says it should be the same
Here a template engine benchmark that tests PHP vs Smarty and many more template engines http://www.raintpl.com/PHP-Template-Engines-Speed-Test/
For assignment Twig is the faster, it compile the html template to a classes, so it's also faster in executing more than the PHP include! IMHO is heavy (many files) and complicate, but is very fast!
For looping the faster is the PHP include, and soon after there's Rain which is very easy, small (1 file) and fast.