Laptop Memory

Laptop memory comes in several shapes and sizes. For purposes of sorting, memory can be grouped by physical size.This process identifies the physical characteristics of the ram. Once that is done, it can be further separated by location of the rejection slot on the ram. This slot is in different locations depending on the operating voltage and characteristics of the ram.If ram is not identified with a label showing details about speed, slot position and voltage can be used as an alternative to specific identification. Once grouped, the remaining task is to sort in Meg or Gig sizes. As with most laptop components a close fit is not enough. Modifying components to fit will create problems or may permanently damage the laptop; ram memory is no exception. The different types of laptop ram are identified below.

Types of Laptop Memory

• Memory Resource for major laptop manufactures
• General information for how memory works
• Excellent article on types and function of RAM

Laptops rarely use the standard SIMM and DIMM memory modules used by non-portable machines. Instead, you may find:

MODULE	CONFIGURATION	DEFINITION	SIZE	IMAGE
SODIMM	72 PIN 32-bit transfer 2.35" wide 3.3V	Small Outline Dual Inline Memory Module	128-512 Meg
SODIMM	144 PIN 32-bit transfer 2.66" wide 3.3V 144-pin SO-DIMMs have a single notch near (but not at) the center.	Small Outline Dual Inline Memory Module	128-512 Meg	144-pin SO-DIMM 4 Chip
SDRAM	PC100 100MHz, XFER 800MB/s 168-pin SDRAM modules operate at 3.3V or 5V.	Synchronous Dynamic RAM	128-512 Meg
SDRAM	PC133 133MHz, XFER 1.1 GB/s 168-pin SDRAM modules operate at 3.3V or 5V.	Synchronous Dynamic RAM	128-512 Meg
DDR1 SDRAM	PC2100 DDR 266 Mhz 2.5V	Dual Data Rate Synchronous RAM	256 Meg - 1GB	DDR1 SDRAM 2100 8 Chip
DDR1 SDRAM	PC2700 DDR 333 Mhz 2.5V	Dual Data Rate Synchronous RAM	256-512 Meg
DDR1 SDRAM	PC3200 DDR1 400 Mhz 2.5V The rejection slot on the ram changes because the voltage differences between DDR1 and DDR2 prevents interchangeability.	Dual Data Rate Synchronous RAM	512 Meg - 1 GB	DDR1 SDRAM 3200 16 Chip
DDR2 SDRAM	PC3200* DDR2-400. Memory Clock: 100 MHz. Bus Clock: 200 MHz. Data Transfers/Sec.: 400,000,000. 200p SODIMM, 1.8v 200-pin SO-DIMMs have a single notch nearer to one side.	Dual Data Rate Synchronous RAM	512 Meg - 1 GB
DDR2 SDRAM	PC4200* DDR2-533. Memory Clock: 133 MHz. Bus Clock: 266 MHz. Data Transfers/Sec.: 533,000,000. 200p SODIMM, 1.8v	Dual Data Rate Synchronous RAM	512 Meg - 2 GB	DDR2 SDRAM 4200 8 Chip
DDR2 SDRAM	PC5300* DDR2-667. Memory Clock: 166 MHz. Bus Clock: 333 MHz. Data Transfers/Sec.: 667,000,000. 200p SODIMM, 1.8v	Dual Data Rate Synchronous RAM	512 Meg - 4 GB	DDR2 SDRAM 5300 8 Chip
DDR2 SDRAM	PC6400* DDR2-800. Memory Clock: 200 MHz. Bus Clock: 400 MHz. Data Transfers/Sec.: 800,000,000. 200p SODIMM, 1.8v	Dual Data Rate Synchronous RAM	1GB - 4 GB	DDR2 SDRAM 6400 16 Chip
DDR3 SDRAM	PC8500* DDR3-1066 204p SODIMM, 1.8v	Dual Data Rate Synchronous RAM	1GB - 4 GB	DDR3 SDRAM 8500 8 Chip