There are, with most MacBook Pros (exclusive of the Retina display models) only two modifications that you can make without voiding your Apple warranty or AppleCare extended warranty – upgrading the RAM and upgrading the drive in the hard drive bay. If you’ve already upgraded your RAM and simply want more speed, you may want to consider upgrading your old hard drive with an SSD (Solid State Drive).
Also known as a solid state drive, the SSD is one of the most well-known alternatives to an HDD. The latter is, however, the typical storage component that most computers and laptops come with – a hard disk drive. A solid-state drive is a device created to store data on your computer. Some tend to confuse it with a flash drive, but this only happens because it looks like a bigger and much more complex version of the more familiar USB stick. There are some similarities between the two of them, since they both have no moving parts, as opposed to an HDD.