Endurance limits of MLC NAND flash

An extensive effort is being undertaken by the flash community to develop signal processing and error-correction coding schemes that make use of soft information. Using experimental data from a state-of-the-art MLC flash device we demonstrate that the theoretical endurance improvement that such schemes can bring is limited. To investigate further, we develop a parametric channel model that takes into account the effects of cell-to-cell interference and demonstrate that it is the presence of programming errors in the channel that restricts the potential endurance enhancement that soft information can offer.