XP antivirus 2011

XP Anti-Virus 2011 or also known as Vista Anti-virus 2011 and Win 7 Anti-virus 2011 is a rogue program that will be installed on multiple operating system.

XP Antivirus

What's new in Google's Android 2.3 Gingerbread?

Part of the fun of owning an Android phone is receiving the updates -- you never know what new treats will arrive when one appears on your phone, like Santa coming down the chimney on Christmas Eve

GingerBread

Lenovo ThinkPad X1

Slimmer than Kate Moss after a month on the Slender diet is Lenovo’s gorgeous ThinkPad X1 laptop, details of which have just shimmied on to the InterWebs

Lenovo Thinkpad

Evolution of Cell Phone

Cell phones have evolved immensely since 1983, both in design and function

Evolution of Cell Phone

Samsung Galaxy S2 Review

The Samsung Galaxy S2 brings the Power of Love Samsung's history in the smartphone game has been pretty quiet – a few budget offerings, some false starts with Windows Mobile and the popular Galaxy S is pretty much it

Samsung Galaxy S2 Review

Wednesday, March 23, 2011

Solid state hard drive (SSD)

A solid state drive is a storage device that uses solid state memory to store data. While technically not a disk, a solid state drive will often be referred to as a solid state disk drive, or a solid state disk, in reference to the fact that, in some ways, it replaces the traditional hard disk drive. Hard disk drives have been a faithful servant to computing for many years. But with heads, platters, magnetic surfaces, spindles and an array of other complex moving parts, they are most certainly fallible. They can be slow, too: disks have to start spinning if they're not already doing so, then they have to get the head to the correct position on the disk to read or write the data. Add this to the physical problems occurring when a piece of dust or other foreign object gets into the mechanism, or when an impact jolts the drive, and we have a distinctly imperfect system. Solid state drives address many of these timing and structural problems inherent in the hard disk drive.
Solid
The principle behind solid state drives is that there should be no moving parts: no spinning platters, no moving heads. Data is split into word length pieces and stored in memory. It is then accessed almost instantaneously using unique system-wide addresses. This behaviour has been used in computer RAM for many years, but for a long time it was too expensive for manufacturers to consider using it as persistent storage in sufficient volumes to replace the hard disk drive.
Solid state disks use either NAND flash or SDRAM (non-volatile and volatile storage respectively). NAND flash is so-called because of the NAND-gate technology it uses and is common in USB flash drives and many types of memory card. NAND flash based drives are persistent and can therefore effectively mimic a hard disk drive. Synchronous dynamic random access memory (SDRAM) is volatile and requires a separate power source if it is to operate independently from a computer.
Solid state drives may be preferred over traditional disk drives for a number of reasons. The first advantage is found, as mentioned briefly above, in the speed of operation. Because hard disk drives need to be spinning for the head to read sectors of the platter, sometimes we have to wait for spin up time. Once the disk is spinning, the head must seek the correct place on the disk, and from there the disk must spin just enough so that the correct data is read. If data is spread over different parts of the disk (fragmented) then this operation is repeated until all the data has been read or written. While each individual operation only takes fractions of a second the sum of them may not. It is often the case that reads to and writes from the hard disk are the bottleneck in a system.
Because the information on solid state drives can be accessed immediately (technically at the speed of light) there is no latency experience when data is transferred. Because there is no relationship between spatial locality and retrieval speed, there is no degradation of performance when data is fragmented.
Consequences of the increased speed of writes for fragmented data include a much decreased application start up time: SanDisk, for instance, claim to have achieved Windows Vista start up times of around 30 seconds for a laptop with its SSD SATA 5000 2.5.
Solid state drives also enjoy greater stability over their disk counterparts. Because there are no moving parts there is less that can go wrong mechanically. Dust entering the device ceases to become a problem (and in any case solid state drives can be sealed air tight unlike disk drives which require a certain air cushion to function properly), and dropping the drive is less likely to cause damage to the data. There are no heads so head crashes are a thing of the past.
This speed and stability comes at a price, of course, and in early models prices of even the most modest of solid state capacities greatly surpassed that of the largest hard disks.

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