The RAM did yield higher scores when our iMac booted off of the stock 1TB hard drive. During a multitasking test, in which we zipped a 4GB folder, converted 42 AAC files to 160 kbps MP3s in iTunes, and ran a Speedmark script in Photoshop, the RAM upgrade helped to shave nearly a minute off of our Photoshop test and about 30 seconds off of our zip folder time. Ultimately, the iMac with a 1TB hard drive and 32GB of RAM scored a 239 in our aggregate Speedmark tests, 12 points higher than the stock iMac with 4GB of RAM.

Adding RAM helps most when using hard drives. When working with multiple applications or extremely large files, if your app runs out of RAM, it needs to get data from your main storage. Spinning hard drives are much slower than RAM or an SSD. If your main storage is an internal SSD, a huge RAM upgrade may be overkill for all but the most demanding of users and tasks.

Before you decide you want to open up your iMac and upgrade the components, make sure you are confident in your ability to perform this upgrade without destroying your computer. OWC's kit has the tools that you will need (other companies such as also sell tools for working on your computer), but doesn't make the task at hand any easier. You may want to find a service that will perform the upgrade for you. All that said, adding an SSD to an iMac will certain boost its performance, and can be a more affordable way to make a great machine even better.