Storage control system with power-off time estimation mechanism and method of operation thereof

A storage control system comprising:

• a power-down module configured to power off a memory sub-system;
• a decay estimation module, coupled to the power-down module, configured to estimate power-off decay in respective blocks of a set of blocks of the memory sub-system upon the memory sub-system powering up, wherein the estimated power-off decay for a particular block is a numerical value indicating how much data in the particular block of the memory sub-system has decayed while the memory sub-system has been powered down, and the estimated power-off decay for the particular block is calculated as a function of a difference between a pre-power-down threshold voltage and a post-power-up threshold voltage;
• and
• a recycle module, coupled to the decay estimation module, configured to identify blocks in the memory sub-system for which the estimated power-off decay has reached a threshold and recycling at least the identified blocks in the memory sub-system for data retention;
• wherein the decay estimation module is configured to calculate a power-off time for indicating how long the memory sub-system has been powered off and estimating the power-off decay as a function of the power-off time.