Computer Memory

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Computer Memory

A memory is used to store information and instructions. Computer memory is the storage space of the computer, where the data is processed, the memory is divided into smaller parts. Each location or cell has a unique address, which changes to one size of memory size from zero.

Memory is primarily of three types −
 Cache Memory
 Primary Memory/Main Memory
 Secondary Memory

Cache memory
Cache memory is a very high-speed semiconductor memory which increases the CPU speed. It works as a buffer between the CPU and the main memory. It is used to capture data and parts of the program. The parts of the data and programs are transferred by the disk operating system in the cache memory, where the CPU uses them.

The advantage of Cache Memory is as follows :
Cache memory facility is as follows:
• Cache memory is faster than main memory
• Useless access to major memory
• It saves the program that can be edited in a short time.
• It stores data

The disadvantages of the Cache memory is as follows :
• The cache memory has limited power
• It is very expensive.
Primary memory
Primary memory only stores information and instructions that are currently working on the computer. It is made of semiconductor devices generally limited to power and power off. These memories are not as quickly as the registers. Important information and instructions for main memory These sub-divisions are divided between Ram and Rom.
Primary/Main Memory features :
• These are semiconductor memories.
• It is known as the main memory.
• Usually unstable memory.
• Data is lost while power is off.
• It is the computer’s working memory.
• Faster than secondary memories.
• A computer can not run without primary memory.
Secondary memory features :
This type of memory is also called external memory or non-volatile. It is slower than the main memory. These are used to permanently store data/information. The CPU does not directly reach these memories, instead, they are accessed through the input-output routine. The contents of secondary memories are transferred to the main memory, and then the CPU can use it. For example, disk, CD-ROM, DVD, etc.

Features of Secondary Memory : 
• These are magnetic and optical memories.
• It is known as a backup memory.
• It is an unstable memory.
• If the power stops, the data is stored permanently.
• It is used for storing data in a computer.
• The computer can run without secondary memory.
• Slow down from primary memories.

Memory is not disk storage ?
It is quite common to question for new computer users to be confused, although each Hard drive and RAM are measure the memory, it is too talk about “memory” or “primary memory” and “storage” or ” Secondary storage “.
When someone asks what the volume quantity in your computer is, usually it is between a MB and 16 GB random access memory (RAM) and hundred or thousand gigabytes or a computer memory unit of magnetic disk drive storage. In alternative words, you have more than Hard Drive Storage compared to RAM.
Why is memory important or needed for a computer?
Not all devices on laptop or pc work on the same speed and memory offer your computer an area to access information. All of the devices on a computer do not operate at the same speed and computer memory gives your computer a place to quickly access data. If the CPU had to wait for a secondary storage device like a hard disk drive the computer would be much slower.

Units of Measure of Computer Memory
1 Bit = Binary Digit
8 Bits = 1 Byte
1024 Bytes = 1 KB(Kilo Byte)
1024 KBs = 1 MB(Mega Byte)
1024 MBs = 1 GB(Giga Byte)
1024 GBs = 1 TB (Tera Byte)
1024 TBs = 1 PB (Peta Byte)
1024 PBs = 1 EB (Exa Byte)
1024 Ebs = 1 ZB(Zetta Byte)
1024 ZBs = 1 YB(Yotta Bytes)
1024 YBs = 1 Bronto Bytes
1024 BBs = 1 Geop Byte