Hey, a couple of days ago I upgraded the ram in my iMac and didi a clean install of Yosemite. Ever since, there has been a strange noise coming from it. It is not randomised and sounds almost like dial up internet but there is a strict pattern. it goes buzz buzz buzz and then beep beep beep, it almost sounds like there is a cricket inside it or something, it is slightly louder than the fan and I'm pretty sure its not the HDD. Does anyone have any ideas? The RAM was crucial and took it to 16gb, I added another 2x4gb sticks. EDIT: I put 900gb through it after the clean install, I though maybe that had over stressed it, I've just checked activity monitor because istat menus is showing the hard drive being written to, turns out file vault still hasn't finished. I think the noise is/could be coming from the SSD part of the fusion drive?