12 (3 banks of 4) This indicates that there are 12 memory slots. These are divided into 3 banks, and each bank consists of four memory slots. So you must add memory four pieces at a time (and they must be the same size and type of memory) in order for the system to benefit from the upgrade.
Your computer’s motherboard sports slots into which memory is plugged. What’s important is how those slots are filled with memory; you can’t just plug memory into the motherboard willy-nilly.
Understand memory slot configuration
There are several ways that a motherboard with four memory banks can host common amounts of memory: 1GB or 2GB. Because DIMMs come in different memory sizes, memory can be set up in a variety of ways inside any PC. (Note: Not all motherboards have 4 slots. Some have more, some less.)
You may have many reasons for choosing different arrangements of memory in a PC. For instance, a single 2GB DIMM an cost ten times as much as a 256MB DIMM. Conversely, a reason for using, say, two 1GB DIMMs rather than four 512MB DIMMs to get 2GB of memory is expandability. Upgrading memory is easier later, when memory slots are available.
Some PCs have a pairing requirement. The memory slots are organized in pairs, and every pair must have the same DIMM size. For example, you can have 3GB of memory in a PC with four memory banks. That’s two 1GB DIMMs in two slots and two 512MB DIMMs in the other two slots.
Yes, you may end up throwing away memory to upgrade. If your PC is configured with 1GB of memory using 4 256 MB DIMMs and you want 2GB of memory total, you have to throw away all the 256MB DIMMs and replace them with a combination of DIMMs.
Get the right DIMM
Not all DIMMs are alike. You must know the memory type, memory chip’s speed, and number of connectors, or pins.
There are several common types. Your computer uses only one memory type, and you must pick a DIMM that matches the type.
| Type | Description |
|---|---|
| DRAM | The official name of a RAM (Random Access Memory) chip: Dynamic Random Access Memory |
| DDR | A Double Data Rate RAM chip, also known as DDRRAM, which is an improvement on SDRAM |
| DDR2 | Another implementation of the DDR type of SDRAM chip |
| DDR3 | Yet another implementation of the DDR type of SDRAM chip |
| EDO | The Extended Data Out RAM chip |
| FPM | The Fast Page Mode type of DRAM chip |
| SDRAM | A type of DRAM chip, Synchronous Dynamic Random Access Memory |
| In addition to getting the right type, you also have to ensure that you buy the correct memory speed. And, finally, you have to get the right number of pins. Some DIMMs are 100-pin, some are 184-pin, and others are 200-pin. |
The easiest way to know what kind of memory you need is to use a computer program to determine how much memory is installed in your computer and how best to update. Computer programs can figure out this stuff without the need to open the computer case.
One program that works well for this purpose can be found at www.crucial.com, which also, coincidentally, sells computer memory. Visit the web-site. Use the Crucial system scanner tool; follow the directions on the web page. Eventually, it tells you exactly how to upgrade your PC’s memory.
Memory buying tips
- Computer memory buying tips.
Before getting started
- Ensure you are familiar with ESD and its potential dangers.
- When installing the memory, make sure the computer is off and unplugged.
Locate memory slots and install memory
DIMM (DRAM, SDRAM, and DDR) memory installation steps
NoteWhen handling memory, hold it by the sides at each end of the module. Be careful not to bend, flex, or drop the memory while handling it. When pushing the memory into the computer, do not apply an excessive amount of pressure. Doing so could cause damage to the memory module, as well as the slots on the motherboard. Finally, when installing the memory, distribute the pressure evenly by pressing on both corners of the memory module.
Once the memory is purchased, locate the memory slots on the computer motherboard. If no memory slots are available on the computer, one or more memory modules must be removed before the memory can be installed.
NoteIf the computer has a small form factor, it may be difficult to access the memory slots. You may have to temporarily remove cables or expansion cards before you can access them easily. When disconnecting anything from the computer, make sure you can remember where each cable and card goes.
Each slot on a motherboard that supports a DIMM is a bank; therefore the computer works if one memory module is purchased.
Examine the memory module before installing it into the computer. At the bottom of the memory module, you should notice one or more notches at the bottom of the card. These notches look like those shown in the picture below.
Make sure that the notches match up with the memory slot you are installing the memory into. These notches allow the memory to be installed only in one direction. If the memory is incompatible, it will not physically match with the slot.
After verifying the notches and direction, the memory needs to be installed, move each memory slot tab out or away from the memory module. These tabs will snap into place as the memory module is installed.
Once these tabs are moved out, gently and firmly push the memory module into the slot. As the memory module is being pushed, the two tabs should snap and hold the memory module into place.
After the memory is installed in the computer, plug the computer back in, and turn it back on. As the computer is booting, the memory should be automatically detected and set up. If you have any difficulties with the memory detected or set up, enter the BIOS setup and verify the memory is correctly detected by the system.
RIMM memory installation steps
What makes RIMM memory modules different from DIMM memory modules is the C-RIMM memory module. This module allows the computer to have a continuous flow of data. When installing a new RIMM, remove the C-RIMM. This module is a small circuit board and has only a few or no chips on it.
When the C-RIMM module is removed, and the two tabs are in the outward position, push the RIMM memory module to a vertical or 90-degree angle. As the memory module is being pushed, the two tabs should snap and hold the memory module into place.
Installing notebook (laptop) memory
Before the memory can be installed into a notebook, the memory slots must be located. If you are unfamiliar with where these slots are located, below is a listing of possible locations:
- On a compartment on the bottom of the laptop.
- Under the keyboard.
- In the computer.
If you cannot locate the slots after looking at each of the above recommendations, we recommend you contact the computer manufacturer for additional help and information.
Once the slots are located, the next step is to install the computer memory. Today, most laptops follow the same memory installation.
Because laptops are thin when compared to a desktop computer, the memory banks are horizontal with the laptop. The memory must be inserted at an angle (approximately 75 degrees). Once it is in the slot, press down on the memory to snap it into place. The memory should also lay horizontally with the computer.
SIMM memory installation steps
30 and 72-pin SIMM memory modules must occupy a bank. Computers that use 72-pin SIMMs have two sockets as one bank. Therefore, two memory modules of equal value must be installed in pairs, unless instructed otherwise by the computer or motherboard manufacturer.
The installation of most SIMM memory is the same. The memory must be entered at an angle, about a 75-degree angle and while still in the memory slot, moved to a vertical or 90-degree angle. As the memory module is moved to a vertical position, it should snap into place. When installed, ensure that both sides of the memory module are snapped into place. If a memory module is not installed properly, it could cause damage to the computer.
We recommend the larger memory modules be installed in the lowest available banks. For example, if the computer has two 4 MB memory modules and you're installing two 32 MB memory modules, place the 32 MB memory modules either in banks 0 and 1, or 1 and 2.
NoteSome computer manufacturers may require SIMM modules be installed in a certain order. So, if your new computer memory installation does not work, consider switching the location of the memory.
Set memory in BIOS
Once the memory appears is installed into the computer, test it. Put the case back on the computer. Connect the keyboard, monitor, and power to the computer. Turn on the computer.
TipWe recommend you do not connect the rest of the cables yet. If you experience problems, you may have to disconnect all the cables again.
As the computer is booting, enter the BIOS and either set the memory to its proper settings or verify that the computer's memory is detected. Once changed or verified, save the settings, exit BIOS and reboot the computer.
For additional help and information, see our BIOS guide.
Troubleshooting
Which Ram Slots To Use First
- Computer memory help and support.
Does It Matter Which Ram Slot I Use
Additional information
- See our memory definition for further information and related links.