CHF QUIZ 2

• Hard Disk


  A sealed case containing one or more circular platters or disks that store data, instructions and information
• Hard Disk


  • Used by the computer system for storing crucial and important data
  • Non-volatile in nature so it can store data even if no power is supplied
  • Data or programs stored are preserved unless it is intentionally wiped out or overwritten
• 5 ¼" Form Factor


  Based on original drive bay size, obsolete
• 3 ½" Form Factor

  Introduced by Sony in 1991, used a reduced width and depth but with similar height as the half-height 5 ¼" form factor
• Advantages of 3 ½" Form Factor

  • Enhanced rigidity
  • Manufacturing ease
  • Increase in speed
  • Power conservation
  • Noise and heat reduction
  • Improved seek performance
• 2 ½" Form Factor


  Introduced by Prairie Tek in 1988, best suited for laptop and notebook PC's
• Common 2 ½" Form Factor Thickness

  • 8.5 mm
  • 9.5 mm
  • 12.5 mm
  • 12.7 mm
  • 17.0 mm
  • 19.0 mm
• Reasons why most manufacturers prefer thinner size

  • Size reduction
  • Power reduction
  • Enhanced rigidity
• 1.8" Form Factor


  Introduced by Integral Peripherals in 1991, mounts seamlessly in most PCMCIA (now called PC Card) slot and very ideal as detachable storage for laptop and notebook systems
• 1" Form Factor


  Developed by IBM in 1988, also called MicroDrive with platter approximately the size of a quarter and capable of storing 4 GB or more
• PATA (Parallel Advanced Technology Attachment)


  Also known as IDE (Integrated Drive Electronics), an older interface that was commonly used for connecting hard drives, CD/DVD drives, and other storage devices to a computer
• SATA (Serial Advanced Technology Attachment)

  A newer interface that was developed as a replacement for PATA, uses a serial data transfer method
• SATA and PATA Comparison

  • SATA uses serial data transfer, PATA uses parallel data transfer
  • SATA offers faster data transfer speeds, up to 6 Gbps, PATA is slower, with a maximum speed of 133 Mbps
  • SATA uses thinner cables with a smaller connector, PATA uses wider ribbon cables with a larger connector
  • SATA can support longer cable lengths, up to 1 meter, PATA has limited cable length of 45 cm or less
  • SATA devices consume less power than PATA
  • SATA is not compatible with PATA devices, PATA can be backwards compatible with older devices
  • Most newer storage devices use SATA interface, older storage devices use PATA interface
• Logic Boards


  Contains the electronic controller and bus adapter circuit, data and power connectors, configuration jumpers/switches
• Hard Drive Interfaces


  • Integrated Drive Electronics (IDE)
  • Serial ATA (SATA)
  • Small Computer System Interface (SCSI)
• Integrated Drive Electronics (IDE)


  The controller is integrated into the disk drive, AT Attachment (ATA) Enhanced IDE (EIDE), Parallel AT Attachment (PATA)
• Serial ATA (SATA)


  Has several advantages over PATA, including superior cabling and connectors, higher bandwidth, and greater reliability
• Small Computer System Interface (SCSI)


  Standard for communication between a subsystem of peripheral devices and the system bus, can contain and be used by up to 7 or 15 devices, provides better performance and greater expansion capabilities for many internal and external devices including hard drives, CD-ROM drives, DVD-ROM drives
• HDD Operation


  1. HDDs are composed of rotating disks or platters with heads that reads and writes data in circular rings

  2. Read and write heads do not make contact with the media

  3. When power is applied, the platters spin up to speed and the buildup of air under the heads causes them to lift off the data surfaces

  4. During power off operation, the platters spin down, the cushion of air dissipates and the heads drop back to the surface of the drive

  5. Newer drives make use of unload/load mechanism that does not allow the head to touch the surface of the platter even if it is powered off
• Tracks and Sectors
• Hard Disk Cylinders
• Solid State Drives (SSDs)

  A type of storage device that use NAND-based flash memory to store data, have no moving parts and store data electronically
• Interfaces of SSDs


  • SATA
  • mSATA
  • M.2 SATA
  • M.2 NVMe
• NVMe Solid State Drives

  NVMe stands for Non-Volatile Memory Express, a type of interface protocol that is designed to allow Solid State Drives (SSDs) to communicate with the rest of the computer system more efficiently than traditional storage interfaces such as SATA or SAS
• NVMe Gen 3 vs NVMe Gen 4

  • NVMe Gen 3 uses PCIe 3.0 interface with up to 8 GT/s per lane, NVMe Gen 4 uses PCIe 4.0 interface with up to 16 GT/s per lane
  • NVMe Gen 3 SSDs typically have a maximum read and write speed of around 3,500 MB/s, NVMe Gen 4 SSDs typically have a maximum read and write speed of around 7,000 MB/s
  • NVMe Gen 4 is also backward-compatible with PCIe 3.0