Storage Hardware Devices

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Storage Hardware Devices

• Presented by
• Hector Arreola
• Valentin Kifumbi
• Keely Ritchie-Boland

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Storage Hardware

• Hardware that saves data and programs
• Nonvolatile Memory
• Memory that preserves data contents without power
• Very reliable
• However, they do occasionally fail

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Storage Hardware Devices

• Magnetic Disks
• Hard Drives
• Optical Disks
• CDs
• DVDs
• Universal Serial Bus (USB) Storage Devices

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Magnetic Disks

• Use magnetism to store data on a magnetic surface

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Hard Disks

• A type of magnetic storage
• Records data onto platters coated with a thin
  layer of magnetic material
• Usually installed inside the computer's case

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Hard Disks Cont.

• Rotational delay
• The faster the disk spins, the shorter the
  rotational delay
• Seek time
• Determined by the make and model of the disk
  device

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Optical Disks

• Circular disk made of plastic and coated with a
  photosensitive material
• Tiny pits store data
• Digital data (1s and 0s) read by reflection

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2 Different Optical Disks

• CD
• Data layer is near the top of the disc
• DVD
• Data layer is in the middle of the disc
• Can have data in two layers
• Have greater capacity and speed than CDs

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2 Different Optical Disks

• Three different types of CDs DVDs
• Read-only Memory (ROM)
• Recordable (R)
• Rewritable (RW)
• CDs DVDs can be used as storage but main use is
  entertainment

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USB Storage Devices

• A of flash memory storage
• Solid-state devices (no moving parts)
• Read and write data electrically
• Memory stored on a small printed circuit board
• Advantages over other storage hardware devices

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Magnetic Disks

• Long term nonvolatile data
• Rotation delay Time it takes for the data to
  rotate under the read/write head.
• Seek time Time it takes to read/write arm to
  position the head over the correct circle.
• Faster spinning disk means shorter time delay.
• Channel Common standard is the ATA-100,
  transfers rate is 100MB per second

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Optical Disks

• Some are read only memory
• CD Maximum capacity of 700MB
• DVD Maximum capacity of 4.7 GB with a
• Transfer rate is 10 times faster than CD.
• Today every computer should at least have a
  CD-ROM

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Hard Disks

• Capacity The number of bites it can hold. Its
  between 10 and 40 gigabytes.
• Data rate The data rate is the number of bytes
  per second that the drive can deliver to the CPU.
  Rates between 5 and 40 megabytes per second are
  common.
• Seek time The seek time is the amount of time
  between when the CPU requests a file and when the
  first byte of the file is sent to the CPU. Times
  between 10 and 20 milliseconds are common

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Brand Names

• IBM
• Toshiba
• San Disk
• Sony
• Philips
• Seagate
• Macromedia

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Price Range
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Summary of Storage Capacity

• Media
• Good for
• Capacity