[wp-hackers] Memory outages and wordpress

[mailapera]

After months of memory outages I installed a capcha plugin to reduce
the spam comment posting. The memory outages disappeared, so I
inquired my hosting (I have a vps) as I have no clue of what resources
intensive commenting could take up.
This was their response
"Wordpress is fairly resource intensive. You may look into installing
one of the various caching plugins, and do some research on the term
wordpress performance optimization"

I did not know WP was resource intensive, it seems a short hand reply
to me, if not a BS reply. However I would like some opinion on this
please. I have about 300 visits per day on the server, and 1G of ram.
Thanks