RAM vs ROM. ( DIFFERENCE & SIMILARITY BETWEEN THEM)- 2018 OCTOBER

 WHAT IS THE DIFFERENCE BETWEEN RAM & ROM

By ABINASH KUMAR PARIDA

RAM (RANDOM ACCESS MEMORY)	ROM (READ ONLY MEMORY)
1. IT IS A TEMPORARY STORAGE	IT IS A PERMANENT STORAGE
2.RAM IS VOLATILE (VOLATILE MEANS IT DELETES EVERYTHING IT CONTAINS AFTER SWITCH OFF)	IT IS NON-VOLATILE
4. IT REQUIRES FLOW OF ELECTRICITY TO WORK.	IT STORES DATA EVEN WHEN THERE IS NO ELECTRICITY
5.FASTER THAN ROM	IT IS SLOWER THAN RAM
6.CAN BE READ, WRITE & ERASE DATA NUMEROUS TIMES	IT ONLY READS & ERASES DATA.
7. STORAGE CAPACITY: -512MB- 256GB (PER CHIP)	STORAGE CAPACITY PER CHIP IS 4MB or 8MB.
8.BIG IN SIZE (BIGGER THAN ROM)	IT IS SMALLER IN SIZE THAN RAM
9. EXPENSIVE	COMPARATIVELY CHIP
10. CAN QUICKLY SWITCH BETWEEN TASKS	CANNOT SWITCH BETWEEN TASKS QUICKLY.
11. WORK AS INTERNAL MEMORY	IT ALSO WORK AS INTERNAL MEMORY
12. DATA IN RAM CAN BE MODIFIED	DATA IN ROM CANNOT BE MODIFIED
13.RAM IS NECESSARY FOR CPU PROCESS	ROM IS NECESSARY FOR BOOT-UP PROCESS
14. FIRST INTRODUCED OCTOBER 1970	FIRST INTRODUCED IN the 1980s.
15. SPEED IS MEASURED IN MHz (1GHz=1000MHz) more GHz means better speed	SPEED IS MEASURED IN MHz. More GHz means more speed.

SIMILARITY BETWEEN RAM & ROM
1. Both store information in their body
2. They represent pieces of information as a series of binary numbers (1&0)
3.ROM stores data even when there is no electricity. But both RAM & ROM work when there is electricity/voltage. (simply, they are nothing without electricity).

THE ACTUAL DIFFERENCE BETWEEN RAM & ROM

1. RAM  (RANDOM ACCESS MEMORY)

1. Why it is called RANDOM ACCESS MEMORY OR RAM?

It is called random memory access because it can access any memory location without touching any lower memory locations.

2. ADVANTAGES OF RAM

 RAM is faster 

3. DISADVANTAGES OF RAM

RAM is expensive 

4. Types of  RAM:- 

TYPES OF RAM
1.SRAM (STATIC RAM)
2.DRAM (DYNAMIC RAM)
3.SDRAM (Synchronous Dynsmic RAM)
4.SDR-SDRAM (Single Data Rate SDRAM)
5.DDR-SDRAM (Double Data Rate SDRAM)
6.GDDR-SDRAM (Graphics Double Data Rate SDRAM)
7.FLASH MEMORY
8.ADRAM (Asynchronous DRAM)
9.RDRAM (Rambus-DRAM)
10.CDRAM (Cache DRAM)
11.FPM-DRAM ( Fast Page Mode DRAM)
12.EDO-DRAM (Extended Data Out DRAM)
13.VRAM (Video RAM)
14.MRAM (Magneto Resistive RAM)

2. READ ONLY MEMORY  (ROM)

1. Why it is called ROM?

During initial computer era computers used to have PROM (programmable-ROM). During that time ROM manufacturers used to write programs on ROM. Users had only able to read the program but they couldn't erase & re-write the program.

That is why we still call it READ ONLY MEMORY. But it is not a correct idea to call ROM as READ ONLY MEMORY. Because modern ROMs differ from initial ROMs.

2.ADVANTAGES OF ROM

ROM is cheaper and can store more. 

3.DISADVANTAGES OF ROM

ROM is slower compared to RAM. 

4. Types of ROM 

TYPES OF ROM (READ ONLY MEMORY)
1.PROM (Programmable-ROM)
2.EPROM (Erasable PROM)
3.EEPROM (Electrical-EPROM)
4. FROM (Flash ROM)
5.MROM (Masked ROM)