What it is: RAM stands for random-access memory, which is used by your computer to run programs. Generally the more RAM you have, the faster your computer will be.
Some Macintosh computers only come with 4Gb of RAM, which is barely enough. Others come with 8Gb of RAM, which is fine for most people. If you run lots of programs simultaneously or use heavy-duty programs to do video editing, run multiple operating systems in virtual machines, or massive spreadsheet analysis, then you might need 16Gb of RAM.
The problem with some Macintosh models (such as the newer Mac mini, the 21-inch iMac, and all the latest Macintosh laptops, is that you can’t upgrade the RAM. Once you buy some of these Macintosh models with a certain amount of RAM, that’s all the RAM you’re going to get unless you’re willing to pay someone to install more RAM for you at a later date, which can get expensive. Generally you want to buy more RAM than you might need today since tomorrow it will come in handy.
The problem with buying more RAM now directly from Apple is that Apple charges far more than the cost of RAM from third-party companies. So it’s actually cheaper to buy a Macintosh with whatever RAM it holds, then buy more RAM and install it yourself. If you want to save money on RAM, then you should limit your choices to those Macintosh models that let you upgrade RAM yourself, which includes the Mac Pro and the 27-inch iMac. Buy the RAM from somewhere else, install it yourself, and you’ll save hundreds of dollars.
The key is to make sure you buy a Macintosh that allows user-installed RAM. When shopping for a Macintosh, look for a phrase in the technical specifications such as “user-accessible
SO-DIMM slots.” user-=accessible means you can open a panel yourself and DIMM slots explain the type of RAM chips you’ll need to buy to plug into those slots.
As Apple continues making their computers smaller and thinner, they keep eliminating user-accessible RAM slots, so check carefully before buying any Macintosh. RAM is cheap. Buying RAM from Apple is not. So make sure you save a little money buying RAM from anywhere else and install it yourself — if you can with your particular Macintosh model.
Before you buy a macintosh, check the Crucial Memory site to see if you can install more RAM yourself and what type of RAM you need.