Optical Storage Systems
As compared to magnetic memory, optical memory is a relatively new secondary storage medium. It has provided to be a promising random medium for high-capacity secondary storage, as it can store large amounts of text of data in limited space.
An optical-disk storage system consists of a rotating disk, which is coated. With a thin metal or any other material that is highly reflective. laser beam technology is used for recording/reading data on a disk. Due to this, optical disks are also known as laser disks or optical laser disks.
- Storage Capacity –
It refers to the amount of data that can be stored in an optical storage system. It is directly proportional to the spot size and the geometrical dimensions of disk.
- Data Transfer Rate –
It refers to the speed at which data can be read from the optical storage systems. It depends on the linear density and the rotational speed of the drive.
- Access Time –
It refers to the time taken to access the desired data from the optical storage systems. It is directly proportional to the weight of head and rotation speed of the disk.
Merits and Demerits :-
|1||The cost-per-bit of storage for optical disks is very low.||It is read-only (permanent) storage medium. Data once recorded, cannot be erased and hence, the optical disks cannot be reused.|
|2||The use of a single spiral track optical disks an ideal storage medium for reading large blocks of sequential data such as music.||The data access speed for optical disks is slower than magnetic disks.|
|3||Due to their compact size and light weight, optical disks are easy to handle, store, and port from one place to another.||It requires a more complicated drive mechanism than magnetic disks.|