The 840 EVO joined the club with firmware EXT0DB6Q, which itself is a nasty little hack around a fundamental design problem with the tightly packed NAND cells.

The 840 EVO joined the club with firmware EXT0DB6Q, which itself is a nasty little hack around a fundamental design problem with the tightly packed NAND cells. Linux 4.0.5 ships with the patch linked above, but for a while you had to roll with a kernel built from source. EDIT: The blatant file corruption issues only manifested after updating to firmware EXT0DB6Q.