Dell Dimmension 3000 is so loud!!!

I own a 8400 and it's awesome. I can't even tell if on or not since is so silence. Well anyways I went over to my friend house. He have a Dell Dim 3000 2.8ghz and is so loud. I was wondering if it's just a model thing or is there something wrong with the computer? What do you guys think? Any Dim 3000 owner out there?