Just wondering what the experts think. Until now Power Options was always set at "Always On". The monitor was always on, the hard disks were always on, the computer never went to sleep. Recently I installed Windows 7, and I found out that it would still put everything in "sleep-mode" with default settings. I have 3 disks, C+F + D + E. Until now I put the Personal Folders on E for safety, but now I tried something different. Windows runs on C, and the Personal Folders and the page file are on the other partition which is F. When I don't use the other 2 drives they sleep, so they should have a longer life. When I use them they have to wake up (spin-up) but that doesn't happen very often in one day. An other point is that the drive that is running will stay cooler because the other 2 are not running. Am I better off just letting the other 2 disks run without using them, or is it better to let them sleep and wake them up when I use them? I'm talking in the long term, after a couple of years?
Average life of drives is 5 years, so if 2 years is your outlook, theres nothing to worry about with either option. Heat is the biggest enemy of electronic components, frequent starts and stops is IMO worse than letting the drives run all the time because that way there is frequent heating/cooling aka frequent expansion/contraction of drives which can lead to mechanical failure. You can monitor the health of your drives with SMART or the manufacturer's diagnostic (like Seatools).
Yes, heat is a problem but, the biggest cause of HD failure or data loss is power loss or not having a battery backup that keeps your power clean and stable.