
Because nearly every computer operation relies on memory, it’s essential to have as much of it as possible, which is why a memory upgrade is one of the best ways to improve Mac performance.

A memory upgrade is ideal for improving responsiveness, running apps faster, and smooth multitasking. If your Mac is a 2011 model or newer, check out how much memory it can be configured with, according to Apple specifications: iMac®, Mac Pro®, MacBook Pro®, MacBook®, and Mac mini®.

For example, in OS X El Capitan, the memory you have installed (amount of GB, speed, and level of memory technology supported – i.e., DDR4, DDR3, etc.) will be displayed as part of the Overview pane. This step varies depending on the version of the operating system and model of Mac being used.

There are easier ways to solve this problem than spending a lot of money buying a new computer. Identifying corrupt files or programs is important, however, slow performance usually has a far less sinister origin. If your Mac is running slow, software and programs you've added might be to blame, causing problems behind the scenes.
