@ is extremely slow. @$arr['key'] is the same as $er = error_reporting(0); $arr['$key']; error_reporting($er); unset($er); Probably more

@ is extremely slow. @$arr['key'] is the same as $er = error_reporting(0); $arr['$key']; error_reporting($er); unset($er); Probably more importantly is that the internal errors are still being raised, there's just additional comparison logic within the PHP engine to suppress them internally.