Lost Circuits article on HDD data transfer rates.

Lost Circuits has written an in-depth article on hard disk media, covering aspects of HDD performance, such as transfer rates depending on the zone position (inner to outer diameters), discrepancies between internal transfer rates and benchmarked rates as well as the impact of track slew.

Some of the internal mechanical magic is also described, which helps explain how manufacturers configure their hardware and sector layouts to maximise performance. All very informative.

The website is slow, so be patient!