HDD (Hard disk Drive) is the basic storage in any computer. HDDs access data with a moving head located on an arm. HDDs consists of many removable parts, making it easy to get damaged with small knocks and bumps. Disk capacity of HDDs range from a few Giga Bytes (GB) up  to many Terra Bytes (TB). Because of the mass production of these devices, the prices are very reasonable and seem to continue to drop.

SSD (Solid State Drive) is a type storage which is made of solid state electronic memory chip arrays, and is composed of control units and memory units (including Flash chip and DRAM chip). There are no moving parts in SSD and thus the speed of these devices is substantially faster than HDDs. Although the cost of SSD is relatively higher than that of HDD, SSD prices are dropping all the time as the production and demand continue to rise.


SSD has the following advantages over HDD:

  1. Faster read-write speeds: SSDs do not have a moving head that reads the data, instead, it use flash memory as the storage medium, and the seek time is almost ZERO, without any delay. No matter what you are running on your Mac, SSDs are compatible, and the running speed has a quantitative leap in performance.
  2. Non Perishable: SSDs do not contain any removable mechanical parts internally, so it can calmly face vibration, overturn and drop, minimising the possibility of data loss when a laptop is accidentally dropped.
  3. Less heat dissipation and zero noise: since SSD adopts flash memory chips, it gives out little heat. Also, because there is no mechanical motor, the noise value is nearly 0 db.
  4. Portability: compared with the traditional HDD, SSDs are smaller in volume and lighter in weight, making it a lot better to carry around.