It doesn't sound faulty, but $3800 and this is the loudest desktop computer I have ever seen. I got the 2TB fusion, 4.0 GHz i7, Radeon R9 N395 and upgraded to 24 GB RAM. I have 2 external 21.5" monitors connected, but the CPU usage is at about 10% and the fan is as loud my late 2012 27" was at full CPU usage. In fact, an app update installation woke me up a few nights ago. Is this typical behaviour for the 5K iMac?