In a typical well-conducted review of a number of high-performance USB 3.0 drives, a drive that could read large files at 68 MB/s and write at 46 MB/s, could only manage 14 MB/s and 0.3 MB/s with many small files. When combining streaming reads and writes the speed of another drive, that could read at 92 MB/s and write at 70 MB/s, was 8 MB/s. These differences differ radically from one drive to another; some drives could write small files at over 10% of the speed for large ones. The examples given are chosen to illustrate extremes....′[46]
With wide deployment(s) of flash drives being used in various environments (secured or otherwise), the issue of data and information security remains important. The use of biometrics and encryption is becoming the norm with the need for increased security for data; on-the-fly encryption systems are particularly useful in this regard, as they can transparently encrypt large amounts of data. In some cases a secure USB drive may use a hardware-based encryption mechanism that uses a hardware module instead of software for strongly encrypting data. IEEE 1667 is an attempt to create a generic authentication platform for USB drives. It is supported in Windows 7 and Windows Vista (Service Pack 2 with a hotfix).[47]
The various writable and re-writable forms of CD and DVD are portable storage media supported by the vast majority of computers as of 2008. CD-R, DVD-R, and DVD+R can be written to only once, RW varieties up to about 1,000 erase/write cycles, while modern NAND-based flash drives often last for 500,000 or more erase/write cycles. DVD-RAM discs are the most suitable optical discs for data storage involving much rewriting.
“The DataTraveler's tiny metal frame and prominent key ring make it easily portable,” our tester said of this flash drive. He added, “Downloading files off the drive itself is fast and easy, at over 100 MB/s, and it's also one of the cheapest USB 3.0 flash drives you can get.” The downside? “While read speeds were fine, the DataTraveler struggles to actually copy files onto the drive,” our reviewer explained. “Despite supporting USB 3.0, it barely tops write speeds of 10 MB/s, and lacks any other features.” The takeaway: “We'd only recommend this product as a cheap way for business professionals to pass out digital content to clients, or for networking,” he stated.
Optical storage devices are among the cheapest methods of mass data storage after the hard drive. They are slower than their flash-based counterparts. Standard 120 mm optical discs are larger than flash drives and more subject to damage. Smaller optical media do exist, such as business card CD-Rs which have the same dimensions as a credit card, and the slightly less convenient but higher capacity 80 mm recordable MiniCD and Mini DVD. The small discs are more expensive than the standard size, and do not work in all drives.
There's a lot to choose from when it comes to buying a flash drive. The most important thing to consider is size. The whole point of a USB drive is to store lots of data in a small space, so think about what kinds of files you'll want to house on your flash drive. Movies and music take quite a bit of space, so if you're carrying your whole entertainment library with you, you'll want a big thumb drive – at least 16GB. Books and other text-based documents require relatively little storage space, so people like students and working professionals using Microsoft Office would be happy transferring Word documents or Excel files with as little as 1GB of space. On the other hand, if you are using photo or music editing software, you'll want a USB flash drive with lots of storage capacity to transfer graphic and music files.
