Encoding Method

The encoding method of the disk refers primarily to the algorithm(s) used to change user data into a pattern of bits that can be stored on the platters. This isn't nearly as simple as it sounds; therefore, several different but related methods have been developed over time to facilitate this conversion (and of course, subsequent conversion in the other direction when the data is read back from the disk.)

Improved encoding methods have one main impact on hard disk performance: they increase recording density, and thus areal density. This improves positioning and transfer performance as described in those sections. Encoding methods are discussed in detail in this section; it contains a relevant comparison between the different methods used over the years, showing how data density has been increased as they have been improved.

Like hard disk read/write heads, encoding method is rarely discussed in hard disk performance circles because it doesn't change very often, and also because it doesn't vary greatly from one drive to the next. Mostly, its effects are bound up in the areal density specification, as well as the transfer rate specifications.

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