Solid State Disks Members: Rakesh Dudi Tianhao Sun Timothy Wease

CONTENTSCONTENTS Background Introduction How a SSD works Advantages and Disadvantages Current Use of SSDs

A solid-state drive (SSD) (also known as a solid-state disk though it contains no actual disk, nor a drive motor to spin a disk) is a solid-state storage device that uses integrated circuit assemblies as memory to store data persistently. Modern 2.5-inch SSD used in both laptops and desktop computers. A rackmount SSD storage appliance based on DDR SDRAM. An mSATA SSD with an external enclosure

In the early 1980s, a Japanese called Fujio Masuoka invented the first flash memory while working for Toshiba. In the mid 1950s, as the transistor was emerging from IBM research,IBM developed their first bulk solid state nonvolatile memory called the Charged Capacitor Read Only Store (CCROS). It was the first true SSD

SSD technology primarily uses electronic interfaces compatible with traditional block input/output (I/O) hard disk drives, which permit simple replacements in common applications. Additionally, new I/O interfaces, like SATA Express, have been designed to address specific requirements of the SSD technology.

Flash Discs are made of many solid-state flash memory cells, which are generally made from a single special flash transistor. To run the flash bit cell, 12 V of voltage is applied to control the gate - which accelerates the process of hot carrier injection into the floating gate.

Basically speaking, a new SSD can speed up your computer in several ways: · Boot times will be significantly reduced. · Launching applications will occur in a near-instant. · Saving and opening documents won't lag. · File copying and duplication speeds will improve. · Overall, your system will feel much snappier.

SSD technology has been developing rapidly. Most of the performance measurements used on disk drives with rotating media are also used on SSDs. Performance of flash-based SSDs is difficult to benchmark because of the wide range of possible conditions. Some Mtron solid-state drives

Write amplification is the major reason for the change in performance of an SSD over time. Designers of enterprise- grade drives try to avoid this performance variation by increasing over-provisioning, and by employing wear-leveling algorithms that move data only when the drives are not heavily utilized. Some Solid State Drives

Solid State Disk Advantages Superior performance as compared to spinning disk Two to three times faster data access rate Not susceptible to jarring and movements Lends itself to mobile platforms such as notebook computers No moving read head benefits Minimal noise if any at all Fragmentation is not a concern

Solid State Disk Disadvantages Higher cost as compared to magnetic disk storage Magnetic disk ~ cost of pennies/gigabyte Solid State Disk ~ cost 1 to 3 dollars/gigabyte Increased failure rate Most cells can only be written to ~ 100,000 times before that cell is no longer functional Wear leveling This is used to evenly distribute writes to all flash cell in the disk. Enables the drive to support number of writes = (# of writes a cell can sustain) x (# of blocks on the disk) Accomplished by maintaining a logical block map inside the SSD device Logical block map creates a High internal storage overhead

Thank You! Credit: Tianhao Sun : Background Introduction Current Use of SSDs Rakesh Dudi : How a SSD works Timothy Wease : Advantages and Disadvantages