Flash drives increasing in capacity and speed

USB flash drives have capacities of up to 256 GB (technology keeps increasing the maximum storage capacity), but the most common sizes are 8 GB and 16 GB, which are generally the best value. Prices generally correspond directly to storage capacity and have plummeted over the past year or two. In January 2008, the average price per gigabyte of flash-drive storage was over $10; however, as the capacity has increased, prices have fallen precipitously. As of August 2010, the average price was a little over $2 per gigabyte in the 32 GB range, and discounts can bring that down to well under $1 per GB.

In terms of functionality, flash drives have replaced floppy disks and data CDs and DVDs, and they are easier to use. CDs only hold 700 MB of data, while DVDs can store 4.7 GB. Flash drives transfer data faster than CD-RW or DVD-RW discs and are more easily portable, as you can carry one in your pocket. Many USB drives have password security or data encryption capabilities, so if you lose your drive, the data is still protected. And capacities are now so high that a flash drive can replace an external hard drive when it comes to backing up your computer files.

While 128 or 256 GB USB flash drives conceivably have enough capacity to back up all the files on most people's computers, their small size makes them easier to misplace. External hard drives have radically greater storage capacities (many measure their storage capacity in terabytes rather than gigabytes; 1 TB  equals 1,024 GB), and cost considerably less per gigabyte. Flash drives are more convenient for transferring files between computers in a home or office, or taking work to and from your office.

The "flash" in flash memory is an electronic signal sent to the memory circuit. Once data has been flashed into memory, the power supply can be removed and the data remains. Data transfer speeds are expressed as a multiple of CD transfer speeds. An 80x USB drive can transfer data at up to 12 Mbps, for example. A 150x drive can transfer data at up to 22.5 Mbps. All connect via a USB port. If you have a USB 2.0 port on your computer, you'll get transfer speeds of about 30 Mbps. The new USB 3.0 specification claims a maximum transfer rate of 5 Gbps, but for USB drives, the range is about 125 to 300 Mbps, which is still a tenfold improvement over 2.0. USB 3.0 drives are also compatible with older USB 2.0 ports, but speeds are much slower.


How USB drives work

Most operating systems recognize USB drives without needing special drivers. The simplest USB flash drives show up as a drive on your computer; you can simply drag and drop files to it. Depending on your auto-start settings, plugging in the drive can automatically open a drag-and-drop window.

More sophisticated USB drives have password protection and/or data encryption. Some USB flash drives have U3 capability (or equivalent), which lets you load and run compatible software from the drive. You can run a program from your flash drive that isn't installed on another computer. When the thumb drive is unplugged, your data goes with you. The software must be optimized for U3, however. You can download programs such as Firefox, Skype and a U3 version of OpenOffice (a Linux-based word-processing and spreadsheet program) from the U3 website, and some come preloaded on the drives themselves.

If you only plan to store data on your USB drive, you might want to skip the U3 capability. Some users express frustration that the U3 software boots up each time they plug in the drive. Though you can reconfigure the drive or uninstall the U3 functionality, this is an extra step.

Reviewers say the following about shopping for a USB flash drive:

  • Decide how much storage you need. Capacity determines price, but prices for smaller sizes (generally from 2 to 16 GB) are often only a few dollars in difference. 32 GB and 64 GB drives are a lot more expensive and the newer 128 and 256 GB products are pricier still.
  • If you plan to store sensitive information on the drive, look for password protection and data encryption. Military-grade technology and Internet backups might seem overkill for some, but useful for others. Some less expensive, general-purpose drives have a small utility that lets you create a hidden secure partition on the drive, as is the case with the Corsair Flash Voyager.
  • Decide if you need a more protective case. If you're rough on your drives, hauling them everywhere and dropping them into a briefcase or bag, choose a drive that's robust and can take the abuse. Some, like the Corsair Flash Voyager, have a water-resistant rubberized case. The SanDisk Ultra Cruzer Titanium is crushproof.
  • Retractable connector vs. a cap? A minority of reviewers like retractable connectors because you don't need to worry about losing a cap. However, retractable designs still leave some of the connector exposed.
  • Consider U3 or similar technology if you want to run applications. If you don't plan to do this, get a regular drive. Many owners ultimately find the U3 software annoying, and for many drives, you have to have administrator access to control the drive's security features. U3 flash drives are PC only.
  • Buy from an authorized dealer. We found many warnings about new and used flash drives purchased through third-party sellers, including complaints of drives purchased on eBay and Craigslist that are either counterfeits or have a lower capacity than advertised.

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