storage hardware devices presented by hector arreola valentin kifumbi keely ritchie-boland
TRANSCRIPT
Storage Hardware Devices
Presented byHector Arreola
Valentin KifumbiKeely Ritchie-Boland
Storage Hardware
Hardware that saves data and programs
Nonvolatile Memory Memory that preserves data contents
without power Very reliable However, they do occasionally fail
Storage Hardware Devices
Magnetic Disks Hard Drives
Optical Disks CDs DVDs
Universal Serial Bus (USB) Storage Devices
Magnetic Disks
Use magnetism to store data on a magnetic surface
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
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
Optical Disks
Circular disk made of plastic and coated with a photosensitive material
Tiny pits store data Digital data (1’s and 0’s) read by
reflection
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
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
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
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
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
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
Brand Names
- IBM- Toshiba- San Disk - Sony- Philips- Seagate- Macromedia
Price Range
Summary of Storage Capacity Media Good for Capacity