A Green NAND SSD Driver (GNSD) driver executes on a host to increase data-retention of flash memory attached to a Super Enhanced Endurance Device (SEED) or Solid-State Drive (SSD). Host accesses to flash are intercepted by the GNSD driver using upper and lower-level filter drivers. A retention-check timer causes a retention routine to be periodically executed. The routine sends high-level commands to the SEED that causes the SEED to refresh either all data or just data blocks with older write dates. Data is refreshed by moving to a new physical block. The retention routine can track write dates of logical blocks and command a SSD to move logical blocks with older write dates. A retention card has a controller that performs the retention routine when not connected to a host, while a SEED power card allows the SEED to refresh data when no host is attached to the SEED.