Memory is an internal temporary storage area for instructions and data that is needed to complete tasks. When you are running programs, parts of your programs may be stored in memory. Memory provides quicker access times than accessing programs or information from a hard drive. As a processor is performing calculations it will also temporarily store pieces of information in memory for quicker retrieval. Memory is temporary storage. If the power is turned off the contents of the memory are lost.

Every computer comes with a certain amount of memory, which is usually referred to as main memory or Random Access Memory (RAM).

There are three types of memory in use today.

1. DIMMS (Dual Inline Memory Module): 168 Pins

Synchronous DRAM (SDRAM): SDRAM can be installed individually or in pairs and has 2 notches in chip

 2. DDR Memory: 

Double Data Rate memory (DDR) is a memory technology that doubles data throughput to the processor. DDR has 184 Pins and 1 Notch on Chip ,can be installed individually or in pairs.

 3. RIMMS (Rambus Ram):           

Rambus DRAM, (RDRAM) a type of memory developed by Rambus, Inc. The memory module used with RDRAM chips. It is similar to a DIMM package but uses different pin settings. Rambus trademarked the term RIMM as an entire word. It is the term used for a module using Rambus technology.

Rambus RIMM modules must be installed in pairs, and they must be identical (same manufacturer and speed – size can differ).

Unpopulated RIMM sockets must be loaded with C-RIMMs (continuity modules) to complete the Rambus channel.

                                    RIMM                                                                                                      DDR Memory

Memory Specifications

Memory is measured by size, megabytes (MB) or gigabytes (GB) and speed (Megahertz). For example 64MB PC133 means the size is 64MB and the speed is 133 MHz.

Memory Problems

Memory modules can cause problems if they are installed incorrectly. Whether they have been plugged in wrong or different types have been installed that shouldn’t be. Memory can also fail sometimes.

Memory Troubleshooting

 Memory troubleshooting is limited.

• Check the memory types to make sure that they are compatible and installed correctly

• Make sure that your motherboard supports the type of memory you are installing

• Try known good memory modules

• Switch the memory around in the slots to insure that all of the slots are functional

Knowledge Check #5

If you have a memory chip that is 256MB PC2100, what is the size and speed of this chip? 

a. 2100MB, 256MHz

b. 256MHz, 2100MB

c. 256MB, 2100MHz

d. None of the above 

Please include your answer to this question in the email that you started previously.

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