How does a HDD physically store info?
Inside the casing there are a series of disk-like objects referred to as “platters”.
The CPU and motherboard use software to tell what’s called the “Read/Write Head” where to move on the platter and where it then provides an electrical charge to a “sector” on the platter. Each sector is an isolated part of the disk containing thousands of subdivisions all capable of accepting a magnetic charge. Newer HDDs have a sector size of 4096 bytes or 32768 bits; Each bit’s magnetic charge translates to a binary 1 or 0 of data. Repeat this stage and eventually you have a string of bits which when read back can give the CPU instructions, whether it be updating your operating system, or opening your saved document in Microsoft Word.
As the HDDs have been developed, one key factor that has changed is the orientation of the sectors on the platter. Hard Drives were first designed for “Longitudinal Recording” – meaning the longer side of the platter is oriented horizontally – and since then have utilized a different method called “Perpendicular Recording” where the sectors are stacked on end. This change was made as hard drive manufacturers were hitting a limit on how small they could make each sector due to the “Superparamagnetic Effect.” Essentially, the superparamagnetic effect means that hard drive sectors smaller than a certain size will flip magnetic charge randomly based on temperature. This phenomenon would result in inaccurate data storage, especially given the heat that an operating hard drive emits.
But, there is one downside to Perpendicular Recording, that is increased sensitivity to magnetic fields and read error, creating a necessity for more accurate Read/Write arms.
WE hope this information was beneficial for you to understand how do HDD's work.
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