How to Find Proper Memory for Upgrading Your Computer

How to match your existing memory to make sure you purchase the correct RAM module for your server/desktop.

Difficulty: Moderate

Instructions

Things You'll Need:

• A computer that needs more memory (runs slow when running powerful or many software programs)
• Tools to open your computer
• Flashlight
• Grounding wrist attachment (optional but highly recommended)
• Some mechanical ability
• Lots of patience

1. 

   Find out how much Memory (System RAM, not HardDrive space)you have. For Windows, right click your My Computer icon and select Properties. Near the bottom it will say for example 512MB or 1GB of RAM. You want 512MB or more for Windows 98-Windows XP; 1GB or more for Windows 2003 or Vista.

2. Head to Google search and enter 'computer memory upgrade' the landscape of sellers changes, so this is best way to find what you need if you have a brand name computer. Choos one of the websites to help you find what you need. Use the below steps to verify that you are purchasing the correct item as restocking fees are always high for RAM. If you want right away, just take this information with you to a local retail outlet. Also note that some RAM must be bought in pairs (i.e. you need 2 or 4 of them).

3. Turn your computer off and flip power supply switch to the off position (usually the 0 label side of 1/0); if no switch, unplug your computers power cable from the computer.

4. Open your computer and find the RAM modules. Try not to touch anything electrical. Put on grounding wrist attachment just in case. If you don't have one handy, just have one hand touching the metal part of your case at all times. (Your static electricity can kill just about anything in a computer!)

5. Write down the numbers of each unique RAM module (physical uniqueness) as you could have a combination of many different sizes and speeds. Note how many used slots and open slots you have. Slot=bank=connector on motherboard a single RAM module snaps into.

6. Take this to a local computer retailer or if you want to order online look for these key items:
   DDR1: PC2100 (266MHz), PC2700 (333MHz), PC3200 (400MHz), PC4000 (500 MHz)
   or DDR2: PC2-3200 (400 MHz), PC2-4200 (533MHz), PC2-5300 (667 MHz), PC2-6400 (800 MHz)
   Unbuffered or Registered (e.g. PC2100R is Registered)
   ECC (typically in servers)
   SDRAM (PC133 168 pins), DDR SDRAM (184 pins), RAMBUS(PC800 184 pins), or DDR2 SDRAM (240 pins) pins=gold contacts along bottom of module.
   CL2, CL2.5, or CL3 (higher number is slower, but match if adding)
   1.8v, 2.5v

7. Check the computer's motherboard manual or the memory upgrade websites found in the google search to see how much total system RAM it can support. Also find out the maximum size a memory module can be. For example, older systems can only use a maximum of 1GB memory modules in each slot.

8. Finally, time to figure out how many and what size to buy. If all your slots/banks are full of RAM modules, you will need to replace some or all of them. Using the total number slots you have, available unused slots, your memory requirements, your budget, and maximum memory size you can calculate what you need. This is best explained as an example, please see next step.

9. Example: You have 4 slots, 2 of which have RAM modules Unbuffered SDRAM DDR PC2100 CL2.5 128MB. This is 256MB of RAM. I want to get to the minimum for Windows XP: 1GB. I need 744MB more memory, but there is no such increment. Memory comes in 256MB, 512MB, 1GB, 2GB, and 4GB increments. So, I need 2-512MB modules at a minimum. I could use 1-1GB memory module, but it is sometimes true that you need to buy memory in pairs. If you don't know, buy in sets of 2 just to be safe. I now purchase 2-Unbuffered SDRAM DDR PC2100 CL2.5 512MB. I add these to my computer which will give me 1256MB of RAM. If PC2100 is out of stock (hard to find now as it is old) you could get PC2700 or PC3200 Unbuffered SDRAM DDR CL2.5 512MB modules.

Tips & Warnings

• Go to http://www.belarc.com/free_download.html to get a free tool to get all kinds of information about your computer.
• SO-DIMM is for laptops.
• You can get faster speed RAM as sometimes the older slower RAM, e.g. PC2100 is not in stock, but you will still need to match all the other attributes. Sometimes a motherboard doesn't know about the faster RAM and needs a BIOS upgrade. Check your motherboard manual for types of RAM it supports.
• 1000MB (megabytes) = 1GB (gigabyte)
• Use a grounding wrist strap when working on the inside of your computer.

[sillysavage]

on 5/5/2008 I just went to crucial.com The site told me what king of memory had in my computer, and what upgrades were available.

[msoexpert]

on 2/20/2008 As someone who's taught computers and has built and serviced them, let me pass along some tips. First, some motherboards don't like when you mix and match different brands so it's generally a good idea to stick with a single brand. This is especially true with some laptops, which tend to be more fickle in terms of memory brands. Second, some older machines don't like the faster memory even though it says it's compatible. For instance, I have one machine that uses PC-100 memory. If I install PC-133, which are backward compatible, the motherboard rejects it. Third, some motherboards require memory be installed in pairs (2 at a time). And lastly, be very careful not to touch the metal pins on the memory modules. They are very sensitive and can short out very easily. Grounding yourself is a great idea, but always hold the memory on the plastic sides.

[AminTaheri]

on 12/11/2006 if you still have your instructions/manual book that came with your motherboard all of that info should be located in there for you already about compatibility, speed, pin requirements, etc.

If you dont, or if you have a prepurchased system (like dell, hp, gateway, or any other 3rd party vendor) they typically have this available in a PDF format on their site. If your in dire straghts you can check what is written on your motherboard for a brand name and a version/model name or number and search on that to get to the manufacturer.