about RAM

1. Subject: RANDOM ACCESS MEMORY (RAM)
Presented by:
 MD. SHAMIM-AL-MAMUN
 Roll : PGD-0909
Mawlana Bhashani
Science and Technology University
Course Title : Computer Organization & Architecture

2. Random Access Memory

3. Index:
 Introduction
 History
 Technology
 Block Diagram
 Position and Structure
 Types of RAM
 Difference
 Capacity to store
 Advantage and Disadvantage

4. Introduction:
 Random Access Memory (RAM) is the best known from of
computer memory.
 RAM is considered as volatile memory, which means that the
stored information is lost there is no power.
 RAM is made up of small chips that from a memory module.
 Whenever you open a program, it gets loaded from the SSD/HDD
into the RAM.
 This is because reading data from the RAM is much faster than
reading data from the SSD/HDD.

5. History:
 RAM was invented by Robert
Heath Dennard
 At IBM Thomas J Watson
Research Center in 1968

6.  Technology:
Type Year
Fpm (Fast page mode) 1990
EDO (Extended data o/p) 1996
SDRAM (Single dynamic RAM) 1996
RDRAM 1998
DDR SDRAM 2000
DDR2 SDRAM 2003
DDR3 SDRAM 2007
DDR4 SDRAM 2014
DDR5 SDRAM 2020

7. Block Diagram of RAM:
 This block diagram introduces the main interface to
RAM.
 A Chip Select, CS enables or disables the RAM.
 ADRS specifies the address or location to read from or
write to.
 WR selects between reading from or writing to the
memory.
 To read from memory, WR should be set to 0

8. Position of RAM:

9. Structure of RAM:

10. Insert RAM into Socket:

11. Eject RAM into Socket:

12. Types of RAM:

13. Types of RAM:
SRAM (Static Random Access Memory)
 SRAM holds data in a static from, as long as the memory has
power.
 Each bit is stored on four transistor that froms two cross
coupled inverters.
DRAM (Dynamic Random Access Memory)
 DRAM is called dynamic because it must constantly be
refreshed and lose the data in very short time.
 DRAM stores each bot of data in a separate capacitor within a
integrated circuit.

14. Difference:
SRAM DRAM
 Requires less memory.  Requires more memory.
 Access time is low.  Access time is high.
 Do not refresh.  Need to be refresh.
 Faster access time.  Slow access time.
 More power consumption.  Less power consumption.
 Used in cache memory.  Used in main memory.

15. Capacity of RAM:
From Beginning:
 256 MB
 512 MB
 1024 MB (1 GB)
 2048 MB (2 GB)
 4096 MB (4 GB)
 8192 MB (8 GB)

16.  Advantage and Disadvantage:
 Advantage:
 Program will load much faster.
 Power Efficient that uses much less power then disk
drive.
 Disadvantage:
 Volatile: a power outage will cause irrecoverable.
 Space-limited: cost per bit is high.