IMacs are typically considered one-piece Macs, with few, if any, upgrades available. You may be surprised to discover that you do have some upgrade options, from simple upgrades that may boost your iMac's performance, to somewhat advanced DIY projects that you may or may not be willing to tackle. Find Your iMac Model Number The first thing you need is your iMac's model number.
Here's how to find it: From the Apple menu, select 'About This Mac.' In the 'About This Mac' window that opens, click the 'More Info' button. The System Profiler window will open, listing your iMac's configuration. Make sure the 'Hardware' category is selected in the left-hand pane. The right-hand pane will display the 'Hardware' category overview.
Make a note of the 'Model Identifier' entry. You can then quit the System Profiler.
RAM Upgrades is a simple task, even for novice Mac users. Apple placed either two or four memory slots in the bottom of each iMac.