3 things manufacturers don't tell you about Solid State Drives (SSDs)
1. Data corruption risks due to poor design and insufficient testing
When removing your SSD device from your computer, it is imperative to disconnect the device safely. Otherwise removing the power while the SSD is reading or writing data means you are taking the chance that the SSD device can shut itself down into a safe state within milliseconds. This is a tall order and to expect it to work every time without fail is hoping the SSD controller designers got their sums right. From our experience as a data recovery company we know occasionally, just occasionally they get it wrong. How do we know, because we see the results where data corruption has occurred and the user has lost access to their files.
2. The life expectancy and capacity reduces over time
Did you know the useful life expectancy of a SSD device could be as little as 5 years under a heavy duty cycle. It is envisaged that most people upgrade their hardware every three years so this should not be a problem unless you buy it second hand. There are currently two types of memory used in SSDs, SLC (single-layer-cell) and MLC (multiple-layer cell). SLC lasts much longer but costs more to manufacture. All the cheaper drives and most USB flash memory drives are MLC based devices. Flash memory can only be programmed and erased a limited number of times. This is often referred to as the maximum number of program/erase cycles (P/E cycles) it can sustain over the life of the flash memory. Single-level cell (SLC) flash, designed for higher performance and longer endurance, can typically operate between 50,000 and 100,000 cycles. As of 2011, multi-level cell (MLC) flash is designed for lower cost applications and has a greatly reduced cycle count of typically between 3,000 and 5,000.
A design phenomenon known as write amplification causes the capacity and the speed of the SSD to reduce overtime. This is due to the fundamental way the SSD erases data from memory.
3. Recoverability and the implications of using encryption
Using full disk encryption can compound SSD data recoverablity problems. Many data loss situations are caused by logical software problems that cannot be recovered from. They cause damage to the encryption disk and this prevents the disk from mounting, which in-turn means the data cannot be decrypted. It also means for badly damaged disks a partial or targeted recovery cannot be attempted as the location of the important data cannot be identified. In these cases it is an all or nothing recovery or it would be like doing a 10,000 piece jigsaw where all the pieces are the same colour.
