The drives we have been using for over a decade record data by magnetizing ferromagnetic material directionally to a surface, to represent either a 0 or a 1 binary digit. They read the data back by detecting the magnetization of the material, which then translates to the data you see on your hard drive. A typical HDD design consists of a spindle which holds one or more flat circular disks called platters, onto which the data is then recorded. The platters are made from a non-magnetic material, usually aluminum alloy or glass, and are coated with a thin layer of magnetic material, most drive platters in consumer hard drives use metal in their makeup.
The drives Achilles' heel is that they consist of many moving parts that are what usually break down and make the drives inoperable, and if dropped the spindle can be broken off. A typical hard drive has two electric motors, one to spin the disks and one to position the read/write head assembly. The disk motor has an external rotor attached to the platters; the stator windings are fixed in place. The actuator has a read-write head under the tip of its very end (near center); a thin printed-circuit cable connects the read-write head to the hub of the actuator. These types of drives use faster rotation speed of the platters to decrease access times, and smaller platters to access the information faster. The WD VelociRaptor is the fastest of the Enterprise SATA drives, offering a 15,000RPM spin rate and using smaller platters for the fastest access times. One thing that makes these drives differ is that standard SATA drives use a controller located usually on the motherboard to control the information flow, where modern SSD devices have an onboard controller. The data flow is limited by the controller and incorporating it into the drive itself has the ability to offer better performance and transfer rates.
SSD devices are completely different in the way they access information and the way the information is stored on them. The original usage of the term solid-state refers to the use of semiconductor devices but in this context, has been adopted to distinguish solid-state electronics from electromechanical devices as well. With no moving parts, solid-state drives are less fragile than hard disks and are also silent, as there are no mechanical delays; they usually employ low access time and latency, which translates to faster boot times and faster access to your information. The performance of the SSD can scale with the number of parallel NAND flash chips used in the device. A single NAND chip is relatively slow. The SSD drive we are reviewing today uses NAND flash memory Multi-Level-Cell (MLC) components made by Intel Corporation, and the Kingston SSDNow M Series 80GB drive has ten of these MLC chips per side making the total a whopping 20.
In 1995 M-Systems introduced the very first flash-based solid-state drives. (SanDisk acquired M-Systems in November 2006.) Since then, SSDs have been used successfully as hard disk drive replacements by the military and aerospace industries, as well as other mission-critical applications. These applications require the exceptional mean time between failures (MTBF) rates that solid-state drives achieve, by virtue of their ability to withstand extreme shock, vibration and temperature ranges. The Kingston has a 2.17 G (7-800 Hz) while in an operating state and 3.13 G (10-500 Hz) during a non-operating state tolerance, which is quite impressive. To help with data access all Intel X25 drives use the Intel branded controller (PC29AS21AA F0C7651.1) and the on-board 16 MB DRAM chip by Samsung. The Intel controller has the ability to do read and write operations across 10 parallel channels simultaneously. All this Bandwidth requires a controller, so a 16MB Samsung DRAM IC is used as a cache buffer for the flash memory controllers ASIC in situations where some of the data needs to only be stored for a split second. This SSD also supports Native Command Queuing (NCQ), which allows drive to accept 32 simultaneous commands at a single time and then dynamically reorder the commands to get the maximum read efficiency. NCQ, when used in conjunction with a hard drive that supports the NCQ feature can really help with the multitasking environment and accessing multiple data streams of information.
