Upgrading your Mac's RAM is one of the simplest and cheapest ways to improve its performance, and it might be more necessary than ever if you're running OS X Lion. While Apple states that the minimum required RAM for Lion is 2 GB, in my experience this is nowhere near enough memory to get Apple's latest OS running smoothly, especially since the latest version of Safari has a nasty habit of chewing through RAM. If you're running OS X Lion on your Mac I'd say the actual minimum RAM is more like 4 GB, and if your Mac will accept 8 GB or more, there's no reason not to max it out if you can afford to.
For some reason many Mac users have got the idea that replacing RAM will void your warranty or your AppleCare agreement. That's not the case at all for the current Macs in Apple's lineup. Apple even provides instructions for swapping out RAM in the instruction booklet that comes with modern Macs, and in OS X Lion the System Information application's RAM tab provides a link to online memory upgrade instructions.
If you're intimidated at the thought of cracking open your Mac, don't be. Swapping out the RAM is easy enough for anyone to do it -- if you know how to use a screwdriver, you know how to swap out your Mac's RAM. In fact, the actual physical process of upgrading the RAM is so easy that the hardest part may be finding the correct RAM in the first place.
It's important to match up the specs of the replacement RAM with what your machine will accept, because otherwise it may not work properly -- or at all. I generally source my RAM from OWC, because their site takes nearly all of the guesswork out of finding the correct RAM for any given model of Mac. OWC even performs testing to discover the actual maximum amount of RAM a Mac will accept as opposed to Apple's often more conservative figures. For example, Apple's official stats for my Early 2008 MacBook Pro state a max RAM of 4 GB, but testing from OWC and other sources shows my model will actually accept a total of 6 GB.
Newegg is another good site to find RAM, and you can often find some good discounts there. However, since it's not a Mac-specific site, you may have slightly more difficulty finding the correct RAM for your Mac.
As general guidelines for optimum performance, it's usually best to make sure your Mac has the same amount of RAM in each slot. In other words, if your Mac has two RAM slots and will accept a maximum of 8 GB of RAM, you're usually going to get far better performance with 4 GB of RAM in each slot than you would with 4 GB in one slot and 2 GB in another, and not just because of the additional 2 GB of RAM. It's also generally a good idea to have all of your Mac's RAM from the same manufacturer. There are exceptions to these recommendations, but you'll want to follow them unless your system is unusual in some way.
Once you've found the right RAM for your Mac, here's a list of what you'll need:
- RAM (it's rather important to remember this)
- Phillips #00 screwdriver (for most Macs)
- A step-by-step guide -- Apple's own guides are decent, but iFixit's are more in-depth
Some Macs are easier to upgrade than others. The MacBook Air's RAM is impossible to upgrade, as it's soldered directly onto the logic board. The pre-unibody models of the Mac mini were notoriously difficult to work on, requiring substantial disassembly to access the RAM, but the unibody Mac mini makes upgrading RAM almost absurdly easy -- you don't need any tools other than your fingers. Mac Pros require a fair bit of disassembly to access the RAM, but that model's modular design makes this relatively easy. The iMac's RAM is also easy to get at, a stark contrast to the risky-looking procedure required to replace its hard drive.
I've focused on portable Macs for our own mini-guide simply because that's what I have access to. Though in most cases they require more disassembly than their desktop counterparts, it's still nothing to balk at if you know how to use a screwdriver.
Pre-unibody MacBook Pro
Swapping the RAM on this model is simple and requires very little disassembly. Remove the battery, remove four screws on the RAM shield and the shield itself, and you're in. I've done many RAM swaps on the older MacBook Pros, and it generally takes me less than ten minutes total.
Servicing this Mac's RAM is also extremely easy. Remove the battery, loosen some captive screws on a retaining bracket and remove that, and you have easy access to not only the RAM but also the hard drive. The pic below is from a recent repair job I did for a friend's MacBook; swapping out both her RAM and hard drive took less than 20 minutes.
Getting at the RAM on this model is very easy thanks to the release levers Apple thoughtfully included. Pushing on the lever causes the RAM to pop out.
Polycarbonate (plastic) unibody MacBook
Getting at the RAM on the unibody Macs isn't quite as "user friendly," as novice users may be put off at the idea of having to expose the entirety of the "guts" of their Macs for a simple RAM upgrade. The good news is that even though you have to remove the entire bottom panel on the unibody MacBooks, Apple's made this very easy. Once again, all you need is a screwdriver and the courage to proceed.
Remove eight Phillips screws (kudos to Apple for not using crazy Y-slotted or security Torx screws) and you'll be ready to remove the Mac's bottom panel. This part can be tricky; in theory the panel shouldn't be exceptionally difficult to lift off at this point, but I had to fight with the panel on my wife's MacBook for a couple minutes before it finally budged. Once removed, your Mac will look like the picture below.
The RAM is exposed and sandwiched between the logic board and hard drive. Removing it is supposed to be easy, but the clearance between the RAM and hard drive was so tight that I found it a bit difficult to remove the RAM from the lower slot. Incidentally, removing the hard drive is also very easy if you happen to be doing that upgrade, too; removing a single retaining bracket with a Torx screwdriver allows you to lift the drive out and swap it with a new one. The procedure for the unibody MacBook Pro is essentially the same for both RAM and hard drive upgrades.
Even though it may seem intimidating to have to remove the entire bottom of your computer for these upgrades, the unibody Macs should be quite easy to service even for novice users. Even though I had to fight with the lower panel and the lower-slotted RAM when I upgraded my wife's MacBook, it still only took about 15 minutes from start to finish.
Once you've put everything back together and started your Mac back up, you can verify that the Mac recognizes the new RAM by accessing "About This Mac" from the Apple menu. If all has gone well, your new RAM will show up and your Mac should feel much snappier overall.