no speed improve

[RohitSavaliya]

i add it and it show all js css file in bottom of page but there is no performance improve it is still 77 before i install it and still 77 after install it
can you please tell me is this really help to speed increase ? or just fix the issue ?

[RohitSavaliya]

additional warnings found on logs

2016-01-07T16:29:07+00:00 ERR (3): Warning: preg_replace(): Unknown modifier '#' in
D:\magento\app\code\community\Pagespeed\Js\Model\Observer.php on line 59

and
2016-01-07T16:29:07+00:00 ERR (3): Warning: preg_replace(): Unknown modifier '#' in D:\magento\app\code\community\Pagespeed\Css\Model\Observer.php on line 59