Cache memory
The rate CPU can fetch from memory is about 10 times slower than the rate at which CPU can process data. Performance of processors often gets limited due to this memory processor speed mismatch obviously, we can improve the all system performance by mincing the memory processor speed mismatch. Each memory is commonly used for this purpose.it is an extremely fast small memory between CPU and main memory whose access time is closer to the prospecting speed of CPU it acts as a high speed buffer between CPU and maim memory and computer system use it to store temporary very active data instructions during processing.
HARD DISK:
A HARD DISK DRIVE (HDD) is a data storage device used for storing and retrieving digital information using rapidly rotating disks (platters) coated with magnetic material. An HDD retains its data even when powered off. Data is read in a random-access manner, meaning individual blocks of data can be stored or retrieved in any order rather than sequentially. EXAMPLE OF PRIMARY MEMORY
FILE SYSTEM IN HDD
1.FAT (File Allocation Table)
It’s not a security.
Partition size is max 32GB.
Does not support data compression.
Does not support disk quota.
2.NTFS (New Technology File System)
It’s a security.
Partition size is 1 (Tera Bytes).
It support data compression.
It support disk quota.
COMPONETS
1. DISK PLATTER
The platter is made up of a magnetic material, in the flat disk part of the drive.
The data stored in the platter.
Each set of magnetic particles is collection a unit called a bit.
2. STEPPER MOTOR
Use stepper motors for controlling read/write head position.
Stepper motors usually use +12V power, but some new low-power drives use +5V power source.
3. SPINDLE MOTOR
It control the platter.
This motor rotates at a speed of 3600 to 10,000 R.P.M
All the platter moves in the same direction.
4 READ AND WRITE HEAD
The heads read and write the information to the drive platter.
The head writes magnetic information on the platter.
SOLID STATE DISK (SSD):
A solid state drive is a storage device used as secondary memory it doesn’t have platter or rotating parts in it. It is made up of storage rom chips. That’s why it is faster then hdd and also expensive in compairing of hdd .
COMPACT DISK(CD):
A compact disk is a storage used to store data in magnetic forms stores 700mb of data comes in read, write and re-write.
COMPACT DISK(DVD):
A digital versatile disk is a storage used to store data in magnetic forms stores 4.7 gb in single layer and 9.4 gb in dual layer of data comes in read, write and re-write.
BLU-RAY DISK(BLU-RAY DISK):
A blu-ray disk is a storage used to store data in magnetic forms stores 25gb of data in single layer and 50gb in dual layer comes in read, write and re-write.
Flash Drives:
A flash drive is a small drive that can be used to hold data. To use it, you insert its metallic side in a USB port on the computer. Once you do, it turns itself on and a window may come up asking you what you want to do. In some cases, the drive would need to install something (a driver) for it to work.
Memory Cards and Card Readers:
The function of a memory card is similar to that of a flash drive except that the card needs a reader for it to be useful. You would buy them separately and insert the memory card into the card reader which is invariably connected to the computer via the USB port
