random access memory
DESCRIPTION
RAM(Random Access memory) is a volatile memory.RAM is our working memory storage. All the data, which the PC uses and works with during operation, are stored here. Data are stored on drives, typically the hard drive. However, for the CPU to work with those data, they must be read into the working memory storage, which is made up of RAM chips. Historical review: Back in the 80's, PC's were equipped with RAM in quantities of 64 KB, 256 KB, 512 KB and finally 1 MB. Around 1990, advanced operating systems, like Windows, appeared on the market, that started the RAM race. The PC needed more and more RAM. That worked fine with the 386 processor, which could address larger amount of RAM. The first Windows operated PC's could address 2 MB RAM, but 4 MB soon became the standard. The race has continued through the 90's, as RAM prices have dropped dramatically. Today it would be foolish to consider less than 64 MB RAM in a PC. The OS like windows Xp requires better than this.TRANSCRIPT
THE M. S. UNIVERSITY OF BARODA
POLYTECHNIC
RANDOM ACCESS MEMORY
SUBJECT:
CREATED BY:
Ruchi M. Maurya
Roll no. 03
S.Y.D. 2nd IT
Random Access Memory
Introduction
History
Technologies
Block Diagram
Position & Structure
Types of Ram
Difference
Capacity to store
Manufacturing companies
Advantage & Disadvantage
Index:
Introduction:
Random access memory (RAM) is the best known form of computer memory.
RAM is considered as volatile memory, which means that the stored information is lost when there is no power.
RAM is made up of small memory chips that form a memory module.
Whenever you open a program, it gets loaded from the hard drive into the RAM.
This is because reading data from the RAM is much faster than reading data from the hard drive
History:
RAM (Random Access
Memory) was invented
by Robert Heath
Dennard.
At IBM Thomas J
Watson Research
Center in 1968.
Fpm (Fast page mode) 1990
EDO (Extended data o/p) 1994
SDRAM (Single dynamic RAM) 1996
RDRAM 1998
DDR SDRAM 2000
DDR2 SDRAM 2003
DDR3 SDRAM 2007
DDR4 SDRAM 2012
Technologies Of Ram:
Technologies Of Ram:
Block Diagram Of Ram:
2k x n memory
ADRS OUT
DATA
CS
WR
k
n
n
CS WR Memory operation
0 x None
1 0 Read selected word
1 1 Write selected word
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. OUT will be the n-bit value stored at ADRS.
To write to memory, we set WR = 1.
DATA is the n-bit value to save in memory.
Position Of Ram:
Structure of Ram:
Notches for socket
”Handles”
Socket
profile
Edge connector
Insert Ram into Socket:
Eject Ram from Socket:
Types Of Ram:
Random Access Memory
SRAM (Static Random Access Memory)
DRAM (Dynamic Random Access Memory)
Types Of Ram: SRAM (Static Random Access Memory)
SRAM holds data in a static form, as long as the memory has power.
Each bit is stored on four transistor that forms 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 bit of data in a separate capacitor within a integrated circuit.
Difference:
• Requires less memory. • Requires more memory.
• Access time is low. • Access time is more.
• Do not refresh. • Needs to be refreshed.
• Faster access time. • Slower access time.
• More power consumption. • Less power consumption.
• Used in cache memory. • Used in main memory.
From Beginning:
256 MB
512 MB
1024 MB (1 GB)
2048 MB (2 GB)
4096 MB (4 GB)
8192 MB (8 GB)
• NOTE: Here every time the size of Ram increased by multiplying twice.
Capacity Of Ram:
ASUS
Buffalo Technology
Century
CEON
CHAINTECH
ELIXIR
HP
IBM
Manufacturing companies:
Advantage:
Disadvantage:
Programs will load much faster.
Power Efficient, that uses much less
power than disk drives.
Volatile: a power outage will cause
irrecoverable data loss.
Space-limited: cost per bit is high.
THANK YOU