OS X El Capitan is now available, and it’s time to upgrade your Mac to Apple’s new operating system, if you so desire. El Capitan will run on all Macs that can run Yosemite, so if you’re running OS X 10.10, you should consider upgrading to OS X 10.11.
If you have older hardware, you may hesitate, thinking that El Capitan might slow down your Mac. Keep in mind that, historically, when Apple released a “revision” version of OS X, such as Mountain Lion or Snow Leopard, these newer operating systems were as fast, or even faster than their predecessors. I’ve only tested El Capitan on recent Macs, but if you’re hesitant, wait a week or so and see what the various Mac websites report about its speed on older Macs.
In addition to the widely-publicized features in a new operating system, there are always under-the-hood improvements that make the upgrade worthwhile. In OS X El Capitan, there are a few key security and privacy features that will make Macs much harder to attack, and that will protect your data.
Read the rest of the article on the Mac Security Blog.