Floppy Disks
Solid State Drives or SSDs
Optical Storage Devices
Flash Drives
Hard Disk Drives
Floppy Disks
A floppy disk consists of a thin, oxide-coated magnetic disk that's protected within a hard, plastic shell. They are largely obsolete. They can store a maximum of 1.44 MB per 3.5" disk and have slow data transfer rates.
They are also vulnerable to damage due to environment conditions such as heat and condensation.
SSDs
It uses integrated circuits to store data. It can be used in place of a hard drive. Like a hard drive it uses SATA(Serial Advanced Technology Attachment) interface and block I/O operations
An advantage of SSD over a hard drive is that it doesn't contain any moving parts. This reduces noise and the potential for damage through wear and tear.
It uses non-volatile memory chips that don't lose data when a system's power is off. This technology makes the SSD faster and more energy efficient but more expensive than hard disk.
Optical Storage Devices
CDs, DVDs are examples of Optical Storage Devices.
CDs and DVDs store data in lands and pits. The lands represent 1 and the pits represent 0 in binary computing. The coputer transforms the binary or digital data into user friendly format.
CDs are 1220 mm in diameter and are 1.2 mm thick. They can store up to 700 MB of data/74 minutes of audio content.
Single sided DVD can store up to 4.7 GB of data/120 minutes of audio content. Dual later can store approximately twice the amount of data as single sided DVDs.
Flash Drives
Small, portable, external storage devices that can store a large amount of data. It uses a flash memory chip which does not depend on electric current to retain data.
Hard Disk Drive
A hard disk drive is a computer's main storage device. It consists of multiple platters coated with a magnetic surface material. The drive reads information from these platters and writes information to them.
The speed at which theplatters spin determines how fast the disk reads and writes information. Modern disk speeds range from 4,200 RPM for low power portable drives to 15,000 RPM for high end server-based drives.
3 Types of Hard drives
IDE (Integrated Drive Electronics)
SATA (Serial Advanced Technology Attachment)
SCSI (Small Computer System Interface)
IDE (Integrated Drive Electronics)
A 40-pin, 80-wire ribbon cable connects an IDE drive and other devices to the IDE interface on a computer's motherboard.Most motherboards with an integrated IDE controller include 2 IDE channels: Primary and Secondary. You can install a master drive and a slave drive on each. Slave drive provide extra storage space or serve as a backup drive.
By default, the master drive on the primary channel is used as the boot drive however you can change this using the CMOS setup program.
You cannot have more than 1 master or slave drives on the same channel.
SATA (Serial Advanced Technology Attachment)
SATA bus uses 2 channels, one for transmitting dataserially bit by bit and another for conforming the reciept of data to the sender.
SCSI (Small Computer System Interface)
External SCSI hard drives connect in a communication chain. Rather than connecting each drive directly to the controller, only the first device connects to the controller and the subsequent SCSI devices connects to the one before it. Using many parallel drives is a benefit of SCSI as it provides constant and reliable access.
The controller has 2 connectors. An internal connector that connects all devices inside a server with a ribbon cable and an external connector connects all external devices to the controller.Each device in the chain has a unique ID. The SCSI controller uses this ID to send data to the appropriate device. Early controllers supports upto 7 devices plus the controller with IDs 0 to 7. Modern ones supports upto 15 devices plus the controller with IDs 0 to 15. The higher a device's SCSI ID, the higher it's priority.