View days ago i am searching solutions for any tips and tricks about
best practice to optimize PHP code performances and i found some of
useful articles which you may interested with. some of article resume

• echo is faster than print.(* compare with list from phplens by John Lim)
• Use full paths in includes and requires, less time spent on resolving the OS paths.
• Unset your variables to free memory, especially large arrays.
• Set the maxvalue for your for-loops before and not in the loop.
• str_replace is faster than preg_replace, but strtr is faster than str_replace by a factor of 4
• Error suppression with @ is very slow.
• Turn on apache’s mod_deflate
• Close your database connections when you’re done with them
• $row[’id’] is 7 times faster than $row[id]
• If you need to find out the time when the script started executing, $_SERVER[’REQUEST_TIME’] is preferred to time()