The drive's media wear indicator ran out shortly after 700TB, signaling that the NAND's write tolerance had been exceeded. Intel doesn't have confidence in the drive at that point, so the 335 Series is designed to shift into read-only mode and then to brick itself when the power is cycled. Despite suffering just one reallocated sector, our sample dutifully followed the script. Data was accessible until a reboot prompted the drive to swallow its virtual cyanide pill.
Who thought this was a good idea? If the drive thinks future writes are unstable, good for it to go into read only mode. But to then commit suicide on the next reboot? What if I want to take one final backup, and I lose power?