Read/Write Head Technology

The read/write heads actually write and read the data to and from the hard disk, so you'd think they'd have at least some impact on the drive's overall performance! And in fact this is true: they do. Improvements to read/write head technologies, and related components such as the head sliders, are key to allowing increases in linear density, which in turn affects areal density and hence both positioning and transfer performance. They also allow further miniaturization of the head sliders and related components, which indirectly allows faster and more accurate positioning performance.

However, you rarely hear read/write heads mentioned in discussions of hard disk performance. The reason it isn't often discussed is not because it isn't important, but rather because it doesn't change very frequently. There have been only five general read/write head technologies used in the last 30 years! So in some ways, nobody talks about the heads because there isn't a lot to talk about. Most manufacturers make the change to new head technologies at roughly the same time. Further, many of the manufacturers license head technology from each manufacturers. Today virtually every disk drive sold uses GMR heads; therefore, this is basically assumed and not really a topic for discussion. This equality in basic design generally leaves only minor tweaks to differentiate head designs between models.

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