You can run "before and after" benchmark tests with a command like this:
/usr/sbin/ab -n200 -c1 -d -S "http://localhost/some_php_page.php"
[robg adds: This hint has been written up as one long bash script with instructions. Instead of reproducing it here, I've uploaded it as a separate text file: install_turck.txt. Click the link to open the file in a new window -- make sure you read all the instructions, as there are manual steps you'll need to take. I have not tested this one.]

