Memory also known as RAM
A laptop memory also know as RAM (Random-access memory) is a temporary data storage. It’s a volatile type of memory. When you turn off the laptop, all the information stored in a RAM module is lost.
More memory installed into your laptop gives you a better (faster) performance.
You can test laptop memory with a free diagnostic tool called Memtest86+.
A type of memory used in laptop computers called SO-DIMM (Small Outline Dual In-line Memory Module).
Here are three most common memory types found in laptop computers:
1. SDRAM SO-DIMM memory has 144pins.
PC100 modules running at 100MHz.
PC133 modules running at 133MHz.
PC133 modules are backward compatible with PC100 modules.If your laptop requires a PC100 memory module, you can safely use a PC133 module but it will run at PC100 speed.
2. DDR SO-DIMM memory has 200 pins.
PC2100 (DDR266) modules running at 266MHz.
PC2700 (DDR333) modules running at 333MHz.
PC2700 memory is backward compatible with PC2100 memory. If your laptop requires a PC2100 module, you can safely use a PC2700 module but it will run at PC2100 speed.
DDR memroy modules are not backward compatible with SDRAM modules.
3. DDR2 SO-DIMM memory has 200 pins.
PC2-3200 (DDR2-400) running at 200MHz.
PC2-4200 (DDR2-533) running at 266MHz.
PC2-5300 (DDR2-667) running at 333MHz.
PC2-6400 (DDR2-800) running at 400MHz.
Faster DDR2 memory modules are backward compatible with slower DDR2 memory modules. For example, if your laptop requires a PC2-4200 memory module you can safely use a PC2-5300 module but it will run at PC2-4200 speed.
DDR2 memory modules are not backward compatible with DDR modules. The notch on DDR2 is located in a different position from DDR.
WHERE MEMORY MODULES ARE LOCATED.
In a laptop computer memory slots could be found in a few different locations, it depends on the brand and model of the laptop.
1. Both memory slots can be accessed from the door on the bottom.
2. One slot is located on the bottom and another one under the keyboard.
3. Both memory slots are located under the keyboard.
4. There is only one memory slot available for upgrades. The main memory is integrated into the motherboard.
HOW TO REMOVE MEMORY MODULE FROM THE SLOT.
Step1.
Release latches on both sides from the memory module with your fingers.
Step2.
The memory module will pop up at a 20-30 degree angle.
Step3.
Carefully pull the memory module from the slot by the edges.
WHAT YOU NEED TO KNOW BEFORE BUYING LAPTOP MEMORY.
1. You are looking for SO-DIMM memory used in laptop computers.
2. Type of the memory used in your laptop: SDRAM, DDR, or DDR2.
3. How many memory slot are available.
4. How much memory your laptop can handle.
Laptop parts | Repair Man | 
December 25, 2008 5:33 pm
April 22nd, 2009 at 7:41 am
I applied pressure to the motherboard and the computer doesn’t boot up any more. Even if I reseat the memory it doesn’t boot. This ones dead. I guess it’s time for a new motherboard or computer.
April 21st, 2009 at 10:32 pm
Mohamad,
There shouldn’t be any difference or change in the laptop performance.
April 21st, 2009 at 10:07 pm
Hi, my laptop require DDr2 PC2-5300 (DDR2-667), I already have 1Gb on slot A (primary) , is that a difference if i install 2GB on slot A & 1GB on slot B or 1GB on A & 2GB on B ?
Thanks for your help.
April 16th, 2009 at 1:03 pm
tbrandis,
That’s a really weird problem. If you tested the laptop with other memory modules and it still does the same thing, the problem must be related to the motherboard. Can you boot the laptop if instead or reseating one one of the memory modules, you apply some pressure on the motherboard in the area of memory slots?
April 15th, 2009 at 5:42 am
I have a Dell D500 that will only boot up if you take one (it doesn’t matter which one) memory card out and reinstall it. It boots up and works fine. then you shut it down and it won’t boot up until you take one of the memory cards out and reinstall. I tried other memory cards and still the same thing.
March 8th, 2009 at 11:00 am
lwebuga,
What is your laptop model? All laptops are different and I can help you if you provide the model number.
March 8th, 2009 at 3:36 am
Hi
My dell Pentium M laptop shows that my RAM is expandable, but the one am using is 506MB , but i want to fix the second empty RAM slot
which type and capacity should i buy ?
January 30th, 2009 at 1:40 pm
Robert,
There could be a problem with the memory module, maybe it’s not making good connection with the motherboard. Try reconnecting the memory module. If you have an empty slot available, move the module into that slot and test the laptop again.
Do you ave two modules installed? Remove them one by one and test the laptop with each one separately.
January 29th, 2009 at 10:22 pm
So I have a sony laptop and I have recently been having trouble starting the computer up. I push the start button and the start-up lights remain on and it will not go to the start-up screen. Then it will stop loading and just stay like that. However, if when I first start it up I hit the button it will sometimes successfully start-up. I don’t know if something is loose inside or what it could be or whatever.
January 13th, 2009 at 2:24 pm
Tamara,
You are welcome! PC2700 is backward compatible with PC2100.
January 12th, 2009 at 11:33 pm
Thank you. I have an older laptop with only one RAM card. The RAM card says it’s PC2100. I wanted to upgrade but couldn’t find another PC2100 card. After reading your article I bough a PC2700 card and installed it myself. The laptop works great with two different RAM cards installed. Thank you again.
Tamara
January 9th, 2009 at 9:03 am
i don’t like kingston value ram. i had a 1gb card for only 2 months and i failed on me.
January 6th, 2009 at 9:16 am
Andrew,
I think both brands are good, I’m using both of them and no problems so far. Also, both have lifetime warranty.
January 6th, 2009 at 8:48 am
I have had good experience with Kingston and Corsair. Both companies offer lifetime warranty for their memory modules.
January 5th, 2009 at 1:38 pm
I plan to buy some more RAM for my Dell Inspiron.
Looking at two brands: Kingston or Corsair. About the same price.
Which one is better?
January 4th, 2009 at 1:10 am
Buy only good RAM brands. I bought cheap RAM, didn’t work first time. Returned back to the store and bought expensive RAM. Works great!
January 3rd, 2009 at 3:40 pm
I was getting blue screens after installed second memory. Returned it back to the store and purchased another one. Works fine now. I guess the first one was bad.
January 2nd, 2009 at 11:01 pm
M.D.
If laptop specs says 1GB, most likely you cannot upgrade to 2GB.
January 2nd, 2009 at 3:27 pm
My lappy is old bought it in 2003.
Specs says maximum RAM is 1GB. Is there any way to upgrade to 2GB???
January 1st, 2009 at 1:46 pm
You are welcome!
I’ve done the same mistake myself.
January 1st, 2009 at 11:55 am
Thank you!!!
My laptop now working fine with new RAMs.
You were right. I wasn’t installing them right.
I have 2Gigs now!
December 30th, 2008 at 8:07 am
Lera,
Make sure the memory module is installed correctly, all the way down into the slot. I think you just not installing it right.
December 29th, 2008 at 11:56 pm
Removed two 512MB RAMs and installed two 1GB RAMs and now my laptop will not start at all??? I know it supports 2GB total. I removed new RAMs and installed old RAMs back, still no boot. Am I doing something wrong?