As we have still yet to get any really good definitive comparisons between the i5 and i7, I am trying to get an idea as to the frequency of hearing the fan come on between the 2 units. So on this thread: i5 users please post how often you hear your fan come on. What tasks prompt the fan to start? Are there certain applications where you notice the fan more than others. Has yours ever overheated and shutdown or given the thermometer error? Please note what kind of a user your are. It will make a big difference if you are simply surfing the web or if your always using pro apps. Your input will help me and others. I am going to post a separate thread for i7 users to answer the same questions. Thanks!