20-06-2012, 02:59 PM
SOLID STATE DRIVE
[attachment=24912]
Introduction
A solid-state drive (SSD) is a data storage device that uses solid-state memory to store persistent data. SSDs are distinguished from traditional hard disk drives (HDDs), which are electromechanical devices containing spinning disks and movable read/write heads.
SSDs use microchips which retain data in non-volatile memory chips and contain no moving parts.
SSDs use NAND-based flash memory, which retains memory even without power. SSDs using volatile random-access memory (RAM) also exist for situations which require even faster access, but do not necessarily need data persistence after power loss, or use external power or batteries to maintain the data after power is removed.
ARCHITECTURE
CONTROLLER-
Every SSD includes a controller that incorporates the electronics that bridge the NAND memory components to the host computer. The controller is an embedded processor that executes firmware-level code and is one of the most important factors of SSD performance.
MEMORY-
SSD manufacturers use non-volatile NAND flash memory in the construction of their SSDs due to the lower cost compared to DRAM and the ability to retain the data without a constant power supply, ensuring data persistence through sudden power outages.
ADVANTAGES
Reliability in portable environments and no noise
No moving parts
Faster start up
Does not need spin up
Extremely low read latency
No seek time (25 µs per page/4KB)
Deterministic read performance
The performance does not depends on the location of data
DISADVANTAGES
Cost significantly more per unit capacity
Limited write erase time
100000 writes for SLC
Leaving to spread writes all over the disk
Slower write speeds because of the erase blocks are becoming larger and larger
CONCLUSION
Today, SSDs are about delivering a premium solution. In the future, SSDs will be about delivering the right solution. SSDs are expanding their presence from niche to mainstream. The declines in the cost of flash and the improvements in capacity and reliability are paramount to the future success of SSDs.
[attachment=24912]
Introduction
A solid-state drive (SSD) is a data storage device that uses solid-state memory to store persistent data. SSDs are distinguished from traditional hard disk drives (HDDs), which are electromechanical devices containing spinning disks and movable read/write heads.
SSDs use microchips which retain data in non-volatile memory chips and contain no moving parts.
SSDs use NAND-based flash memory, which retains memory even without power. SSDs using volatile random-access memory (RAM) also exist for situations which require even faster access, but do not necessarily need data persistence after power loss, or use external power or batteries to maintain the data after power is removed.
ARCHITECTURE
CONTROLLER-
Every SSD includes a controller that incorporates the electronics that bridge the NAND memory components to the host computer. The controller is an embedded processor that executes firmware-level code and is one of the most important factors of SSD performance.
MEMORY-
SSD manufacturers use non-volatile NAND flash memory in the construction of their SSDs due to the lower cost compared to DRAM and the ability to retain the data without a constant power supply, ensuring data persistence through sudden power outages.
ADVANTAGES
Reliability in portable environments and no noise
No moving parts
Faster start up
Does not need spin up
Extremely low read latency
No seek time (25 µs per page/4KB)
Deterministic read performance
The performance does not depends on the location of data
DISADVANTAGES
Cost significantly more per unit capacity
Limited write erase time
100000 writes for SLC
Leaving to spread writes all over the disk
Slower write speeds because of the erase blocks are becoming larger and larger
CONCLUSION
Today, SSDs are about delivering a premium solution. In the future, SSDs will be about delivering the right solution. SSDs are expanding their presence from niche to mainstream. The declines in the cost of flash and the improvements in capacity and reliability are paramount to the future success of SSDs.