PC assembly - Inserting memory modules

Inserting RAM modules

There are various types of random access memory. The latest motherboards are equipped with DDR2 or DDR memory. Some are even equipped with RAMBus memory. The oldest ones actually have SDRAM connectors, or even EDO RAM connectors.

It is generally impossible to insert non-supported RAM into the motherboard as each memory type has one or several notches that prevent it from being inserted into the wrong slot type.

Notches on memory modules.


DDR, SDRAM or RAMBus memory modules can be inserted in memory slots one at a time. It is not recommended to insert memory modules of different types (and brands), for the following reasons:

  • they may be incompatible;
  • the computer is forced to run at the speed of the slowest memory module.

To insert DDR, RAMBus or SDRAM,memory modules just pull open the clips located at each end of the slot, place the memory module straight down into the slot, making sure it is in the correct position (one or more notches between the pins prevent the module from being inserted the wrong way around).

Inserting RAM modules

Press down firmly without forcing. The two clips at each end should close by themselves.


DRAM or EDO RAM must be inserted in pairs, i.e. for 32MB you should install 2 16MB modules.

Inserting EDO memory is quite tricky. Place it into the slot at a 45° angle, then click it in place horizonatally.

Ask a question
CCM is a leading international tech website. Our content is written in collaboration with IT experts, under the direction of Jean-François Pillou, founder of CCM.net. CCM reaches more than 50 million unique visitors per month and is available in 11 languages.
This document, titled « PC assembly - Inserting memory modules », is available under the Creative Commons license. Any copy, reuse, or modification of the content should be sufficiently credited to CCM (ccm.net).