INTRODUCTIONto Memory(RAM)

By Jatin Goyal

Computer memory

Questions in Mind?

3. What are Upgrade limitation of system?

1.What is Computer memory and Why Do We Need It?

2. What are the Type of Computer memory and how they compared?

4. What they mean by multiple channel memory?5. How to identify memory of pc?

RAM Slotflash ROM and CMOS RAM

PRAM

Classification by access

Read-Only Memory Read-Write Memory

• non-volatile • volatile

Volatile Memory losses contents when power is removed

PROM

EPROM

EEPROM

EAROM

Flash CAMDAM SAM

Read-Write Memory

DAM SAM CAM

SRAM DRAM

SIMM DIMM DDR DDR2 DDR3

RAM

PRAM

Read-Write Memory

DAM (Direct Access Memory) - direct access to all memory cells - RAM

SAM (Sequential Access Memory) - data reading in sequence - HDD, optical discs

CAM (Content Addressable Memory) - associative memory - returns value according to

supplied word

The computer can access information held anywhere in RAM by addressing that part of the RAM directly.

e.g if information stored in the 1000th location in memory the system does not have to read the information in the preceding 999 locations to get there, instead it can access the 1000th location simply by specifying it.

RAM (Random Access Memory) Holds data and instructions used by CPU any piece of data can be returned in a

constant time

RAM

SRAM (Static Random Access Memory)- volatile

-does not need to be periodically refreshed- more complex internal structure, more

expensive, less capacity than DRAM

DRAM (Dynamic Random Access Memory)-volatile -to keep information must be periodically

refreshed- structural simplicity, high capacity

 PRAM( phase change memory  )-non-volatiles

Physical type of memory(DRAM)

SIMMs Single Inline Memory Module Pins on opposite sides form a single set of

contacts

1987

EDO DRAM

EDO = Extended Data Out Resides on SIMMs Sends and receives data

simultaneously Maximum transfer rate to L2 cache is

approximately 264 megabytes per second.

1990

DIMM(dual in-line memory module)

Small Outline DIMM(SO-DIMM)DIMM mean module has Ics or chips and connection b/w both side in single line.

DIMMs 1993

Buffered memory put less strain on the electrical load in Memory controller allowing a stable System that has several memory module.

ECC code ability to detect and correct the error during data

transmission.

Non-ECC/Non-Registered DIMM

ECC/Registered DIMM

Non-ECC/Non-Registered DIMM

SDRAM

SDRAM PC66 transfer 533MB/s at 66MhzSDRAM PC100 Desktop Memory transfer   800MB/s at 100MhzSDRAM PC100 Server Memory (ECC)  transfer 800MB/s at 100MhzSDRAM PC133 Desktop Memory transfer  1,066MB/s at 133 MhzSDRAM PC133 Server Memory (ECC)  transfer 1,066MB/s at 133 Mhz

1999

Double data rate SDRAM 2002

DDR 2 2006

DDR 3

within the module and has the added advantage of a 30% reduction in power consumption dropping the voltage from 1.8V to 1.5V

2010

DDR 4(future) 2015

Figure -Timeline of memory technologies based on Standard Organization• Goal of new technology

o Increase overall throughput while retaining accuracyo RAM manufacturers continue to produce older RAM

CURRENT TIME LINE OF MEMORY MODULE

Cl or CAS rating Over Clocking Nomenclature(Identification of module) Ranking Comparison of DDR module notch

CERTAIN TERM

SGRAMSynchronous Graphics RAM

SGRAM is a variant of SDRAM SGRAM makes use of block-writes to

increase video processing speeds. SGRAM is single-ported so the CPU

cannot write to it at the same time the image is being refreshed.

SGRAM is used in high-end graphics cards

How Many & What Kind of Memory Modules Are CurrentlyInstalled ?

Open the case and look at memory slots How many slots? How many filled? Review module imprint

Examine module for physical size and notch position

Read motherboard documentation See if board supports dual channels or triple

channels Last resort

Take motherboard and old memory modules to a good computer parts store for conformation

Speccy  

Virtual Memory

Virtual memory takes the place of RAM memory

You should have a 2:1 ratio of RAM to Virtual Memory

Modifying Virtual Memory in Windows 8

Major Manufacturers

• Corsair Memory• Crucial

Technology• EDGE Tech Corp• GEIL• G.Skill• Hynix• Infineon

Technologies

• Kingston Technologies

• Micron Technology

• PNY• OCZ Technology• Rambus• Samsung• SimpleTech