Types of laptop memory

Over the years there have been several types of Sodimm (Small Outline Dimm Modules) produced in order to keep up with the advancement in technology. When a new memory type is produced the latest type is not backwards compatible.  To ensure that the incorrect ram is not installed each Sodimm has a notch also known as a "Key" in a specific place along the gold contacts. Below we will cover the different types of laptop memory that have been produced. 

144pin SDRAM Sodimm

Sodimm 144-pin SDRAM

SDRAM arrived in 1993 and had replaced almost all other types of DRAM due to its increase in speed.   

Main Specs

  • Speeds: 66Mhz, 100Mhz & 133Mhz
  • Identification: 144pin Sodimms have a single notch near the center of the board.
  • Voltages: 3.3v & 5v

200pin DDR SoDimm

Sodimm 200Pin DDR

Double Data Rate memory was first released in 2000 and was given the name due to being able to provide nearly twice the bandwidth of SDRAM. 

Main Specs

  • Speeds: PC2100 (266Mhz), PC2700 (333Mhz) & PC3200 (400Mhz)
  • Identification: 200pin Sodimms have a single notch nearer to one side.
  • Voltages: 2.5v & 2.6v

200pin DDR2 Sodimm

sodimm DDR2 200PIn

Brought to market in 2003 again providing an advancement in both speed and power. 

Main Specs

  • Speeds: PC2-3200 (400Mhz), PC2-4200 (533Mhz), PC2-5300 (667Mhz) & PC2-6400 (800Mhz)
  • Identification: 200pin Sodimms have a single notch nearer to one side.
  • Voltages: 1.8v

204pin DDR3 Sodimm

Sodimm 204pin DDR3

Around since 2007 DDR3 used lower voltages the is DDR2 predecessor.  

Main Specs

  • Speeds: PC3-8500 (1066Mhz), PC3-10600 (1333Mhz) , PC3-12800 (1600Mhz)
  • Identification: 204pin Sodimms have a single notch off center.
  • Voltages: 1.35v & 1.5v