A benchmark for different ways of using echo in PHP.

echo

<?php
	define( 'ECHO_COUNT', 10000 );
	define( 'EXECUTION_COUNT', 100 );

	function coma( ) {
		for ( $i = 0; $i < ECHO_COUNT; $i++ ) {
			echo 'a ', $i, ' b ', $i, ' c';
		}
	}

	function dot( ) {
		for ( $i = 0; $i < ECHO_COUNT; $i++ ) {
			echo 'a ' . $i . ' b ' . $i . ' c';
		}
	}

	function interpolation( ) {
		for ( $i = 0; $i < ECHO_COUNT; $i++ ) {
			echo "a $i b $i c";
		}
	}

	$results = array(
		'coma' => 0,
		'dot' => 0,
		'interpolation' => 0
	);

	foreach ( $results as $function => $meanTime ) {
		$time = microtime( true );
		ob_start( );

		for ( $i = 0; $i < EXECUTION_COUNT; $i++ ) {
			$function( );
		}

		ob_end_clean( );
		$results[ $function ] = ( microtime( true ) - $time ) / EXECUTION_COUNT;
	}
?>

<table>
	<thead>
		<tr>
			<th>Method</th>
			<th>Mean time for <?php echo EXECUTION_COUNT; ?> x <?php echo ECHO_COUNT; ?> echoes</th>
		</tr>
	</thead>

	<tbody>
		<?php foreach ( $results as $function => $meanTime ): ?>
			<tr>
				<td><?php echo $function; ?></td>
				<td><?php echo $meanTime; ?></td>
			</tr>
		<?php endforeach; ?>
	</tbody>
</table>