Random Posts Not Working with W3 Total Cache Plugin

I use this:
WP_Query("cat=&showposts=6&orderby=rand");

To get random post but its not working with W3 Total Cache!
Is there anyone can help me in this ?

Plugin url: http://wordpress.org/extend/plugins/w3-total-cache/

 

This plugin consumes excessive cpu

 

What about it isn't working?
Check your permalinks, and in the W3TC settings, uncheck URL redirects and then see if that fixes the issue.
If that's not it, uncheck Minify cache.

But more than likely, you should contact your host and insure that you have all of the settings correct.
Unless you are running your own server, it is impossible to know the correct settings without speaking with the host about thier recommendations for the best performance.

If you are running it on shared hosting. Hang it up. It won't do you any good.