Dual In-Line Memory Module

Home » Computer Hardware » Computer Memory » Dual In-Line Memory Module

A Dual In-Line Memory Module (DIMM) describes the physical package and interface to DRAM. It is currently the most common form of memory for PC users to buy or upgrade. Physically, DIMMs consist of several integrated circuits that are mounted on a small interface card (a bit bigger than a stick of gum). The circuit board has a connector on one long edge that has a line of copper or gold-plated contact pads.

Electrically, a DIMM connects to a 64-bit data path on the PC motherboard, and commonly operates at between 3.3 to 5 volts.

Modern PCs generally use DDR or DDR2 DIMMs, which have 184- pin and 240-pin connectors, respectively. There are also 168-, 144-, and 72-pin units, which are either used on older systems or laptops.

Following is the proper way to install a DIMM:

• First, make sure you have a memory unit that is compatible with your PC motherboard. Different DIMMs have different patterns of “notches” on the connector edge. (Plugging in a DIMM backwards, or plugging in an incompatible type, will break your motherboard, your DIMM, or both!) Your PC or motherboard user’s manual will tell you what types of DIMM you can safely use.

• Next, the memory slot on your motherboard will have a plastic tab on either end. These are called Ejector Tabs, and they will lock in place on your DIMM to keep it from falling out later. For now, pull them away from the slot and downward, making room for the DIMM.

• Finally, gently insert the contact edge of your DIMM into the memory slot on your motherboard and close the ejector tabs upwards until they lock onto the DIMM.

Remember to prevent electrical damage by wearing a grounding strap, and making sure the PC is unplugged from the wall before attempting any upgrades.

Next Page: Dynamic Random Access Memory (DRAM)

Related Computer Memory Articles

---

• Random Access Memory
• Read Only Memory
• SIMM
• Static Random Access Memory
• Synchronous Dynamic Random Access Memory
• Electronically Erasable Programmable Read Only Memory
• Erasable Programmable Read Only Memory
• Flash Memory
• Motherboards
• PCMCIA
• Computer Memory Introduction
• Double Data Rate
• Dual In-Line Memory Module
• Dynamic Random Access Memory (DRAM)
• EDO Random Access Memory