Solid State Drives (SSD) store digital data just like Hard Disk Drives (HDD), but they are very different in terms of construction and performance. SSD technology has made a dramatic impact on reliability, speed and performance.
Hard disk drives are electromechanical devices with spinning disks and movable read/write heads. The device needs to wait for these moving parts to get in place before they can write or read any information. This makes them slower, and more likely to fail. SSDs use microchips that retain data in non-volatile memory chips and contain no moving parts. This potentially makes them much faster than HDDs.
SSDs can instantly read and/or write twice as fast HDDs. This is a clear advantage when booting a computer, downloading large files, opening software applications, or working on highly demanding tasks like photo or video editing. A critical deciding factor is the controller (the "brain") behind a SSD. A mediocre controller with a top rated SSD may end up being slower than a conventional HDD.
SSDs do not need to be defragmented, and they stand a better chance of surviving a drop or impact. Strong magnetic fields, like speakers or even cell phones, can corrupt the data on a HDD, while SSDs are unaffected by magnets. SSDs consume less power (2W SDD vs. 7W HDD typical power consumption), and produce less heat, which greatly expands the life and battery performance on laptops and other portable devices.
But Solid State Drives have their downsides, too. One is price. As of early 2012, solid-state drives are currently much more expensive than HDDs. SSDs cost anywhere from $1.50 to $5.00 per gigabyte, while a HDD can range from $0.07 to $0.30 per gigabyte.
HDD prices vary by manufacturer, and greatly depend on speed (5400 RPM vs. 7200 RPM) and connectivity (USB 2.0, USB 3.0, Firewire 400, Firewire 800, eSATA, and Thunderbolt). Regardless, video or photo enthusiasts looking for a compact external hard drive for storage will find the new SSD devices to be much more expensive than virtually any hard disk-type drive – again, as of early 2012.
An important clarification: The limited number of write cycles for SSDs gives them a limited life span. Typical users write 1.4 GB/day, and a heavy mobile computer user may write 5.2 GB/day. Considering a conservative endurance limit of a 64GB (MLC NAND-based) SSD, a heavy mobile user would have to write approximately 22GB of new data per day, every day, for five years to reach the technical life span of that drive. With a 128GB drive, the wear would be spread over a larger storage area, doubling the average daily limit to 44GB.
Therefore the endurance limit is so far beyond the likely usage of a typical user that life span of these recent solid-state drives may not be a realistic cause for concern.
Remember, ALL Drives will fail and die. It is not a matter of IF but WHEN and a backup strategy should be in place regardless which device you chose for your workflow.