Depending on the embodiment, it may be desirable to reduce the overall system load resulting from performing a re-evaluation. Thus, the calibrations performed in operation 568 may primarily be fast calibrations. However, normal and/or extensive calibration operations may be executed when certain block conditions indicate normal and/or extensive calibration would be preferable (e.g., data is uncorrectable with current threshold voltage shift values, etc.). Moreover, the results (e.g., threshold voltage shift values) of a calibration procedure may be stored in a lookup table and/or appended to existing values for the unit of memory.

After operation 568, method 500 proceeds to decision 570 which includes determining whether the calibration of operation 568 was performed successfully. When decision 570 determines that a number of calibration errors (e.g., correctable and/or uncorrectable) experienced during the calibration of operation 568 exceeds a retirement error count limit, it may be determined that the calibration of operation 568 was unsuccessful. As a result of the unsuccessful calibration, method 500 may proceed to operation 508 whereby the result of the re-evaluation is to retire the unit of memory, e.g., from any future use.

However, when decision 570 determines the calibration was successful, method 500 proceeds to operation 572. Accordingly, the success of the calibration procedure may correspond to situations in which a number of calibration errors associated with the calibration process performed on the unit of memory does not exceed a retirement error count limit.