simple configuration

[Friedrich Locke]

Hi folks,

i have just installed varnish and this is my first message to the list.
I did i very simple configuration. I edited /etc/varnish/default.vcl.

I included the following lines:

backend default {
        .host = "aton.cpd.edu.br";
        .port = "80";
}

I stress loaded the my site, now being served by varnish, but i
noticed no performance improvement.
I would like to do a minimal configuration just to see how fast
varnish could do.
Is there something more i need to configure in order to get the taste
of varnish ?

Thanks in advance.