Have you ever wondered how Hard Disk Drives can store billions of bits of data within the volume of a short, small brick? Thinking about it, it’s really truly incredible that a library worth of data, millions of photos, or thousands of videos can be stored in a device that costs less than $100.
source/image: Branch Education
Data storage has truly evolved to incredible densities over the past 6 decades, and in this video, we’re going to see how exactly a Hard Disk Drive stores data, how it reads and writes data, and then the cutting-edge technologies that are continuing to decrease the size of each bit of data.
A modern HDD records data by magnetizing a thin film of ferromagnetic material on both sides of a disk. Sequential changes in the direction of magnetization represent binary data bits. The data is read from the disk by detecting the transitions in magnetization.
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User data is encoded using an encoding scheme, such as run-length limited encoding,which determines how the data is represented by the magnetic transitions.A typical HDD design consists of a spindle that holds flat circular disks, called platters, which hold the recorded data. The platters are made from a non-magnetic material, usually aluminum alloy, glass, or ceramic.
