Western Digital introduces 'Advanced Format' - Up To 10% More Usable HDD Space
 

This is a new format method they will be incorporating into their various drive lines. Advanced Format represents a new way for their drives to handle data internally. Instead of each individual sector having its own Sync/header and ECC, the new format will move to larger physical sectors, in this case 4k. This results in an overall net gain in storage efficiency, so much so that Western Digital was able to save on wasted space even after shifting to a larger ECC block size. Larger ECC is a good thing, as Error Correcting Code is used to detect and correct bit errors that occur within each physical sector. While Advanced Format yields roughly 10% net gain in usable space, Western Digital will be sticking to the round number capacities existing in all current lines.

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