How to make a use of spare memory?

Is there a way to make a use of the spare memory I have?

---

I am using default CMM and just host a Xenforo forum (no members yet). Nothing else and won't host anything else.

And I don't have a clue about system administration, so I didn't change some configs or editted some line of codes or something. I am just asking because why not?

 

1)

Ok, how much do you suggest?
256MB? 512mb? More?


2)

I have read somewhere on here that ngx pagespeed causes a lot of problems, still recommended?
And regarding this manual #3, I just have to add this, right?

Code:

# ngx_pagespeed & ngx_pagespeed handler
include /usr/local/nginx/conf/pagespeed.conf;
include /usr/local/nginx/conf/pagespeedhandler.conf;
include /usr/local/nginx/conf/pagespeedstatslog.conf;

3)

Just have to uncomment them, right?

Code:

#  pagespeed MemcachedThreads 1;
#  pagespeed MemcachedServers "localhost:11211";
#  pagespeed MemcachedTimeoutUs 100000;

4)

These lines?

Code:

innodb_sort_buffer_size=2M
innodb_online_alter_log_max_size=128M

Which one and how much should I raise them?



Thank you so much for your help.

 

Anyone?
Increased memcache to 1024
Inno to 256