You got it. That's the search function, but it isn't the most user friendly. When you use that search box, there are filters that you can choose (news, articles, forum..etc).
I'm sorry but the search function is extremely poor, one should be able to at least whilst viewing a particular forum be able to search just that forum.
If you try searching on AMD Phenom you will not find the message you refer to above - sorry this just does not work.