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Chapter 3
- Optical disc
- Prices and part names from: Chillblast
- SSDs
- Samsung 860 QVO SSD (4TiB): £463.50
- Seagate BarraCuda SSD (1TiB): £110.73
- Seagate BarraCuda SSD (500GiB): £59.41
- Samsung 860 EVO SSD (250GiB): £65.25
- HDDs
- Seagate BarraCuda 7200RPM Hard Disk (1TiB): £40.94
- Seagate BarraCuda 5900RPM Hard Disk (8TiB): £231.10
- Seagate IronWolf Pro 7200RPM NAS Hard Disk (4TiB): £179.41
- Seagate IronWolf Pro 7200RPM NAS Hard Disk (8TiB): £312.51
- Seagate IronWolf Pro 7200RPM NAS Hard Disk (16TiB): £734.99
Exercises
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- Data is written by 'burning' the disc with a high-power laser, changing its chemical properties to make it less reflective; and is read by a lower-power laser that is testing how reflective the surface of the disc is
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- The disc could have been scratched while in storage, rendering the disc unreadable
- The disc could have been exposed to extreme light or heat, corrupting the data on it
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- Solid-state drives have no moving parts - where a hard disk drive has magnetic discs and read-write heads, the SSD has a circuit board with a series of floating gates on it, which trap electrons to measure an 'on' state. Solid-state drives also have no way of unsetting a single gate - an entire 'block' (roughly equivalent to a sector on a HDD) must be cleared at once - whereas the HDD can polarise any individual bit to either state.
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- Faster access
- Lower power usage
- Silent operation
- Highly portable and resistant to shock damage