I have an iMac that I never let sleep because of the belief that desktop hard drives are most reliable when spinning 24/7, and that spin-up/spin-down cycles caused by sleeping or shutdowns stresses them and causes them to break. Of course, I built that belief over many years. Is that still generally true for modern drives? Are the so-called "green" drives, seemingly designed to frequently stop/start what with their automatic sleep modes, hardened against this stress? By contrast, aren't laptop drives are expected to be frequently spun up/down and so are specifically designed to handle it?