Lo. Anyone able to offer a sanity check for me please - just want to ensure all avenues are exhausted checks wise etc. Put together a new machine (key components - Vertex 4 128gb running 1.5 f/w, gigabyte GA-Z77X-D3H - unsure on bios rev, need to check) Periodically, the SSD isn't picked up on boot (which means windows doesn't load etc). Bios doesn't register the drive either. Seems pretty random on what it takes to get it to pickup again - this morning before work 10 or so reboots didn't work. PC worked fine most of yesterday, including a few soft restarts while installing windows etc. The drive is plugged into the bottom port of the two SATA 3 ports on the board. It originally shared with a Samsung F1 but that's since been moved to a SATA 2 port. (Interestingly, when the two shared the SATA 3 ports, neither seemed to be detected on boot when the SSD went missing - could be relevant!) Running CrystalDiskMark the drive averages ~ 350mb read/write on the sequential checks - seemed pretty low for this disk (it's < 50% full) but put this down to it being the OS drive..... The SATA controller is set to AHCI in bios Stuff on the list to check tonight (in a rough order): 1 - Switch Power for another string (it's sharing with SATA DVD-Rom at the moment) 2 - Switch SATA cables 3 - Switch SATA 3 ports 4 - Move the SSD over to the SATA 2 controller 5 - Re-seat the HDD in its caddy 6 - Check HDD bios revision is the latest 7 - Try another drive on the SATA 3 controller (Seagate ST1000DM003) 8 - Remove other HDD's (Samsung F1 and a Hitachi Deskstar) from SATA 2 controller 9 - Re-flash 1.5 firmware and secure wipe the drive TIA!