(Following on from my other thread regarding my dying Mid-2010 MBP) I purchased a new 13" rMBP base model from a local reseller at the weekend, and whilst I'm really impressed by the performance (which also highlighted how slow my old one had become) I just have a question regarding a noise I'm hearing... I assumed that without the constant thrum of a HDD that the machine would be 100% silent (like an iPhone or iPad save for the occasional burst of fan noise) but instead it has a constant high-pitched electrical sound, like a mixture of scratchy beeps and buzzes (similar to the noise some chargers or routers make). The noise isn't loud, but in a quiet room it's noticeable from a normal working distance and if I hold my head over the left side of the keyboard, quite pronounced. Increasing workload (downloading big files or opening an app like Photoshop) increases the noise slightly but at idle it never goes away regardless of screen/keyboard brightness, wifi on/off. I've searched about and seem similar queries (mainly for the 15") but their noises either emit during specific tasks or only under load. So I'm more looking to see other people's experiences and whether this is considered normal?!