Solid state drives, or SSD, have come a long way, evolving rather swiftly than traditional hard drives. The word is that one day, SSDs will replace conventional hard drives. Marking an SSD as your priority storage medium would mean your interests lie in making your computer performance-oriented. While SSD vanquishes the territory of efficiency, speed, and compactness, there has been a lot of buzz around the reliability and durability standpoint as it can only withstand a certain amount of reading and write cycles. Here’s a brief insight into the evolution of SSD and its architecture to get a better understanding of this ambiguity:
DRAM:
Dynamic Random access memory (DRAM) was the primeval member in the family of SSDs. Dynamic RAM stores each bit explicitly on a capacitor integrated into a circuit. Each capacitor in the circuit can be charged or discharged accordingly to represent corresponding binary 1s and 0s. As the charge on a capacitor is subjected to leakage, the data saved on the DRAM is lost within the stipulated time. Due to the following reasons, this ancestor of SSDs ceased to be used as a permanent storage device.
Incorporation of Flash in SSD’s:
In layman’s terms, a flash memory is a memory similar to a pen drive. A flash memory can be erased electrically and is a non-volatile storage medium. 1984 marked the usage of EEPROM in memories; nevertheless, a writing program required a complete erase of data on the EEPROM. This led to the invention of flash-based SSDs. Flash-based solid-state drives enable data to be manipulated at the page level, making reading and writing more convenient. A flash-based SSD can be subdivided into NAND-type and NOR-type. NAND-type flash memories are widely preferred for their properties and contribute to a significant portion of SSDs manufactured.
ARCHITECTURE:
A solid-state drive primarily comprises a controller, memory, battery, cache, and interface.
The controller acts as a bridge for communication between the memory and the computer. A controller is responsible for the execution of code at the firmware level and has other functionality as mentioned below:
- Allocating temporary space for reading and writing operations
- Mapping of bad sectors
- Avoid wearing memory blocks, etc.
A memory, generally a NAND-based flash memory, is widely preferred by manufacturers for its durability rather than speed. A memory is segregated into blocks, and each block is segregated into pages.
To ensure a smooth read and write operation on each block/page, a memory uses a temporary memory called cache, which saves the intermediate information when many parallel read and write operations occur. The controller manipulates the information in the cache.
A battery, sometimes a capacitor, is used to back the cache for flushing the data into memory in case of abrupt power loss.
An interface is the physical bus or connector line which connects the computer and the SSD. Several interface standards are available, and the interface significantly influences the transfer speeds of data. Examples of a few interfaces are Serial ATA, PCIe, Parallel ATA, USB, etc.
After a comprehensive look at the architecture, we are now in a superior state of understanding to get a lucid perspective on SSD failures and their indications:
- Hardware Failure/Component Failure of an SSD: Hardware failure would mean the device shows abnormalities when powered. Most of the time, such a failure can be studied by connecting the SSD to different computers or using a different cable. Any indications of this failure would be the flickering of the power indicator (if any) or the drive not being detected. Interfaces like SATA decrease the transfer or signaling rate between the drive and the computer when many errors are reported to avoid data loss; this can also be one of the significant indicators of a dying drive.
- Failure due to physical damage/ thermal shock: It is pretty standard for electronics to turn faulty when exposed to physical stress; no wonder most electronics have a handle with care and caution. Fortunately, unlike an HDD, these drives may endure physical abuse, but any damage in circuitry cannot be disregarded and can have data loss consequences.
- Failure due to degradation and corrosion: The prime adversary for an SSD’s longevity is corrosion. These failures cannot be perceived until we get a proper look on the internal circuitry. However, they can be avoided by maintaining a virtuous routine.
- Bugs in flash drive’s firmware resulting in corruption or over-writing of data: Frequent loss or corruption of data is the prime indicator of this kind of a failure. Contacting the manufacturer at the earliest would be the best way to avoid any further loss. The errors at firmware level also alter the internal communication process of the control system and cause a corruption of data when information in the cache is not completely transmitted.
- Partial failure due to bad blocks affecting the efficiency: The unit on memory at which erase operations are performed is called a block. A lot of drives are transported from a manufacturer with bad blocks, these blocks are marked as bad by the manufacturer itself. During the deployment as well, a drive can develop bad blocks. Increase in the number of bad blocks would indicate the parallel decrease in usable space on the drive.
SSD’s usually do not give any warning signs as they near failure. When an SSD fails, it no longer works and hence results in huge data loss. What to do when SSD fails that results in huge data loss? In such case, it is really a nightmare task to perform data recovery from failed SSD. However, no need to worry in such situations, as data recovery from failed SSD is still possible with advanced data recovery programs.
Remo Recover is one such data recovery program that recovers data from failed SSD drives on both Windows as well as Mac based platforms, as the software comes out with Windows and Mac versions. Download the demo version of the software and get back your files from the failed Solid State Drive successfully.
