Posts Tagged ‘Usb Interface’

Bharat Bista asked:




Typically USB flash storage devices are small, lightweight, handy, low cost, rewriteable and removable; USB flash drives are NAND-type memory, a data storage device integrated with a USB interface. There are several advantages over other portable storage devices; predominantly on conservative storage devices like floppy disk, USB Drives are faster, grasp more data, and are considered more dependable than any other storage devices available in market today.

By comparison to 88.2 million USB flash drives shipped in 2005, and 115.7 million shipped in 2006, Gartner Dataquest statistics shows average 100% raise on number of USB memory drives user worldwide. SanDisk ranks No. 60 on FORTUNE’s 100 fastest-Growing Companies List.

USB flash drives are a relatively dense form of storage, even the cheapest and smallest flash memory chips will store dozens of floppy disks worth of data. Most flash memory chips today can hold more data than a CD. Top of the line flash drives can even hold more data than a DVD. CompactFlash storage devices ready to hit the market soon include 64 GB’s of PRAM memory. The most common USB flash memory devices are 1GB in size Recent industry reports indicate a rise for the first time in over a year for these 1GB USB storage devices due to their popularity. The flash memory market had recently only been experiencing drops in prices. This is an indicator that the profit margins on memory products may see much more positive profits this quarter.

Most modern operating systems can read and write to USB flash drives without any supplementary device drivers. Instead of exposing the composite technical detail of the underlying USB flash memory devices, the USB flash drives export a simple block-structured logical unit to the host operating system. The operating system can use whatever type of file system or block addressing scheme it wants.
Most USB flash drives do not utilize a write-protect mechanism. Such a switch on the housing of the drive itself would keep the host computer from writing or modifying data on the drive. Write-protection would make a device suitable for repairing virus-contaminated host computers without infecting the USB flash drive itself.

USB flash drives are more tolerant of abuse than mechanical drives, but the rate of USB flash drive failure under eprovided.com statistic shows 300% raise each year due to quality-control problems, mishandling and an increasing number of poorly manufactured devices on the market.

According to expert Bruce Cullen, president of data recovery services eProvided.com, “Similar to other mechanical storage devices USB flash drives also have mechanical storage and threshold margins, and face issues with potential fragmentation problems. This fragmentation occurs when documents are created and then saved or erased and when the new files are bigger than the available adjacent space. The data in these files is broken up and is randomly placed on the drive cells, resulting files start to become fragmented. Issues related to fragmentation are not known to consumers, so consumers aren’t defragging their flash drives properly.”

Generally a consumer is expected to find that a standard single level cell of a NAND flash drive can acknowledged 100,000 read-write cycles, usually an immeasurable amount of read-writes for common users. Issues like virus attacks, damage causes by extreme heat/cold, power outages, shock, etc. can shorten the life span of the drive or cause it to malfunction suddenly in many cases.

However, the real problem for the colossal rise of USB drive failures is manufacturing & quality control issues; faulty flash drives with poorly manufactured specifications in the market are dominating compared to the quality high price drives with similar configurations.

“I expect a dramatic rises in problems with USB flash drives as there are a lot of mushroom companies growing and manufacturing flash storage devices these days” Bruce Cullen said. “Most of the USB flash storage producers are based in Taiwan, Singapore and China, due to price competition these companies are disregarding quality controls, and due to this price competition even quality manufactures are manufacturing and selling products using low-grade flash memory circuits, capacitors and crystals, resulting in massive increases in USB Drive failure rates and reliability issues. This is creating flash memory technology questions on quality” he further added.