Memory module

Two types of DIMMs (dual in-line memory modules): a 168-pin SDRAM module (top) and a 184-pin DDR SDRAM module (bottom).

In computing, a memory module is a printed circuit board on which memory integrated circuits are mounted. Memory modules permit easy installation and replacement in electronic systems, especially computers such as personal computers, workstations, and servers. The first memory modules were proprietary designs that were specific to a model of computer from a specific manufacturer. Later, memory modules were standardized by organizations such as JEDEC and could be used in any system designed to use them.

Types of memory module include:

• TransFlash Memory Module
• SIMM, a single in-line memory module
• DIMM, dual in-line memory module
  • Rambus memory modules are a subset of DIMMs, but are usually referred to as RIMMs
  • SO-DIMM, small outline DIMM, a smaller version of the DIMM, used in laptops

Distinguishing characteristics of computer memory modules include voltage, capacity, speed (i.e., bit rate), and form factor.