How to Upgrade RAM in an Old iMac

If you have an older iMac that is in need of some upgrading, here’s an easy way to add a bit of a performance boost to your old iMac.

One of the cheapest and easiest ways to upgrade any computer is to install more RAM (a.k.a. memory) or replace the current RAM with more gigabytes and faster speeds. Usually it takes only a few minutes and it’s as simple as popping it out and popping new modules back in, with maybe a screw or two getting in the way at first.


On an older iMac, it’s really easy to change out the RAM, and it will give you the most noticeable speed boost aside from installing a solid-state storage drive. A boost in RAM is highly recommended if your older iMac is running a newer operating system, like OS X Yosemite, as it requires 2GB of RAM to operate properly. Since my old iMac only has 2GB, OS X Yosemite would be operating under bare minimum requirements, so I’m going to change that by replacing it with 4GB of RAM.

Without further ado, let’s get started replacing the RAM in an older iMac for that effortless speed boost that you’ve always wanted.

Before You Begin

Before you buy RAM and go to replace the current RAM in your iMac, it’s important that you get the correct kind of RAM. Not only do modules come in different sizes, but they also come in different speeds.


To find out what kind of RAM your specific iMac needs, click on the Apple icon in the top-left corner of the screen and select About This Mac. Next, click the Memory tab and you’ll be shown what kind of RAM you’ll want to get.



As you can see, I would need DDR2 SDRAM modules at 800 MHz. So write this down as you go online and shop for RAM. I like to buy a lot of things on Amazon, but Newegg is also a great place to go for computer components.

Replacing iMac RAM

Once you have your RAM ready to go, it’s now to time to replace the old modules with the new ones.

The first thing you’ll want to do is shut down your iMac and unplug it. Then place it face down on a flat surface on a towel so that you don’t scratch up the display.


On the bottom of the iMac (the edge facing toward you), there will be a plate with a small screw in the center. Take a large phillips screwdriver and unscrew it. The screw won’t come all the way out, so unscrew it as much as you can and then simply just pry the plate off.


Once it comes off, you’ll see two slots that the RAM modules go in. Sometimes there will only one module with the other slot empty or both slots could be taken up.


Next, you’ll see a curled-up plastic ribbon in each slot, carefully pry these out with your fingers and they’ll transform into tabs, for which you then pull on them to pop the RAM modules out of their slots. They won’t come out all the way, so you’ll have to grab them and gently pull them out.



Next, take your new RAM modules and slide them into each slot. They’ll only go in one way, so be sure that you have the pins lined up. If you’re not sure, simply take a flashlight and look inside the slots. There will be a separator toward the left side of the slot between the pins. Line up the RAM modules with this separator accordingly.


Slide the RAM modules into place. You might have to give them an extra shove to get them to slide fully into the slots — they shouldn’t be sticking out.


From there, screw back in the aluminum plate, set your iMac upright again, plug it in, and power it up! Head to About This Mac again and check if your new RAM upgrade is showing up correctly.