I have a 2011-mid iMac, with 3,4Ghz i7, 8GB RAM, 2GB Radeon 6970M and an extra 1TB Samsung EVO 840 SSD added, which runs the OS. The last couple of months I've been seeing some strange behavior, which I am wondering a bit about: • The machine may crash out of nowhere. This comes in two flavors; 1. Everything freezes instantly, or 2. One app gives me the spinning wheel, then the next, then the next, and slowly they freeze so that I can't interact with them. No Kernel panic text. • Machine reboots out of nowhere. Upon a hard reset and reboot, most of the time everything is fine. But I have on two occasions have the following happening: 1. Machine would flash between the folder with question mark (Ie. no bootable OS) and the stop sign. Repeated reboots fixed this. 2. The machine would continuously show the folder with question mark, and then after 5 minutes change to the stop sign, and then a minute later start launching the OS as normal. The latter tells me that it is not a faulty graphic card but likely a disk problem, ie. the SSD, but is that normal behavior for a failing SSD? I thought they just crash and burned at some point, without recovery possible. Edit: Upon wake from sleep, the machine now always trigger apps freezing one after a time. Reboot always gives me the flashing question mark folder for 5 minutes. Disk Utility reports that the disc needs to be repaired, but I can't boot into the recovery disk, since it never shows up when I boot while holding down the alt-button. Any suggestions?