Archive for the ‘Hard Disk Drive’ Tag

Flash Memory – The Little Champ !

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What’s common between a Pen Drive, SD, Mini SD and Micro SD Cards? All of them hold large amount of data in a tiny space. The advent of flash memory has made it possible to shrink the size of memory chips and has found its place in cell phones, Cameras, PDA’s and other portable devices.

Flash is a non volatile memory meaning the data is retained even when there is no power supply. It’s a particular type of EEPROM (Electrically Erasable Programmable Read Only Memory) that is erased and programmed in large blocks. EEPROMs are realized as arrays of floating gate transistors (MOSFETs to be more precise) and hence occupy lesser space. But there’s one characteristic of Flash that makes it unique and advatageous over the typical EEPROM – the electrical interface of a Flash differs from that of the  typical EEPROM. While Flash is read / erased in large blocks, EEPROMs are read/erased bytewise as it has dedicated circuits for each byte. And this characteristic of Flash makes it more affordable.

Solid State Drives (SSD), which use Flash memory, consume only one tenth of the power as that used by Magnetic hard drives. With no moving parts, they are more reliable, rugged and compact. Apple’s MacBook Air, the thinnest laptop in the world, is the first gadget to sacrifice hard disk and optical disk drives in favour of the Solid State Drives. A MacBook Air with 64 GB Solid State Drive costs around $3000 whereas the one with 80 GB Hard Disk Drive costs $1799. Apparently one would have to pay more for a Solid State Drive but it’s worth the benefits it offers. Unlike a Hard Disk even if your laptop is dropped often, the drive won’t crash.

Samsung has unveiled a Hybrid Drive which has a buffer of 128/256 MB cache consisting of Flash memory. By using this large buffer for data storage, the platters of the hard drive are at rest almost all of the time, instead of constantly spinning, as they are in the current hard drives. The data to be stored is temporarily written into the cache, and once the cache is full the data is written into the disk resulting in decreased power consumption and lesser write times.

In future, as prices continue to fall, the Solid State Drives are likely to replace conventional Magnetic Drives. The future of FLASH looks BRIGHT!

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