Specifications
Flash Memory Guide
9
INTERFACE PIN COUNT SIZE IN MM
eMMC 169 BGA 12 x 16 x 1.2
eMMC 169 BGA 12 x 16 x 1.4
7.5 Solid-State Drives (SSD)
A solid-state drive (SSD), is a data storage device that uses solid-state memory to store data with the intention of
providing access in the same manner as a traditional hard disk drive (HDD). As of 2007 most SSDs use non-volitile,
NAND-based Flash memory to retain data and contain no moving parts. Compared to HDDs, SSDs are typically less
susceptible to physical shock, are silent, have lower access and latency times and deliver much higher performance.
SSDs use the same interface and form factor as traditional hard drives thus making them easily replaceable in most
computer platforms.
Kingston oers a broad range of solid-state drives to suit the needs of business professionals, consumers, system
integrators and enthusiast. Kingston’s business class SSDs are some of the fastest in the industry and carry a longer
warranty. Kingston’s consumer and system builder SSDs oer a good balance of price and performance while
enthusiast will enjoy the ultra-fast performance and styling of Kingston’s HyperX SSDs.
The Flash memory chips used in SSDs: There are primarily two types of Flash memory used in SSDs, Multi-Level
Cell (MLC) and Single-Level Cell (SLC). Both types of Flash memory oer dierent performance and endurance
characteristics. Due to the high cost of SLC Flash memory, MLC is becoming the more common Flash memory used in
SSDs built for client-based notebook and desktop PCs. SSDs that are designed for servers will use a new Flash memory
process called Enterprise MLC Flash memory (eMLC) that will oer higher endurance and be more suitable for high-
end server workloads.
SSD Endurance: SSD endurance is the amount of time an SSD can be expected to function normally given a write
workload. SSD endurance is commonly classied in Total Bytes Written (TBW) to the drive. This is the total amount of
data you can expect to write to the drive over its useful life time. Flash memory endurance is primarily reduced by die
shrinks in the NAND and by something called the “Write Amplication Factor” or WAF. WAF is the dierence between
Host Writes and the total amount of data written to the NAND per write operation. Flash memory devices like SSDs
write in full blocks. In order to write to a block that already contains some data requires the good data in the block to
be combined with the new data and rewritten to the Flash. For example, if 2GB of data is written to the SSD the actual
data written to the Flash may be 4GB. In this case the WAF is (2). Depending on the SSD controller and the type of data
being written (random or sequential) to the SSD, the WAF vary from as low as .5 to has high as 20 or 30.
SSD Storage Controllers: SSDs use sophisticated Flash controllers to communicate between the Serial ATA Host
Controller and the Flash chips on the SSD. This special chip manages all the reads from and writes to the Flash memory
on the SSD. The SSD controller also manages other important functions such as wear-leveling and garbage collection
to extend the life of the drive and help maintain consistent performance levels over the life of the drive.
Serial ATA (SATA) Host Interface: All of Kingston’s SSDs support the SATA host interface connection which allows
Kingston SSDs to connect to most mainstream notebooks, desktop and server computers built within the last several
years. Kingston SSDs are compatible with most SATA revision 2, 3Gbps and SATA revision 3, 6Gbps host controllers.
Most SATA host controllers provide for backward compatibility however if a SATA host controller is limited to specic
read and write speeds, using a faster SSD will not result in faster data transfers. For example if a SATA Rev. 3 SSD is
attached to a SATA Rev. 2 host controller, data transfers will only be as fast as the host controller.
INTERFACE Speed VOLTAGE PIN COUNT SIZE IN MM
SATA Rev. 2 3 Gbps 5 Volts 22 Pin SATA 69.85 x 100 x 9.5
SATA Rev. 3 6 Gbps 5 Volts 22 Pin SATA 69.85 x 100 x 9.5