Types of Flash Drives

USB flash drives vs. other storage media

USB flash drives have maximum capacities ranging from 128 MB to 64 GB (new technology keeps increasing the maximum storage capacity). Prices generally correspond directly to storage capacity and have plummeted in the past year. In January 2008, the average price per gigabyte of flash-drive storage was over $10; as of February 2009, the same flash drives can be found for around $3.50 per gigabyte, and we easily found markdowns as low as $1.40 per gigabyte. 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.

USB flash drives do not have enough capacity to back up all the files on most people's computers, even if you use several of them. For that you'll need an external hard drive. External hard drives have radically greater storage capacities (many measure their storage capacity in terabytes rather than gigabytes; one terabyte equals 1,024 gigabytes), 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 that says, "remember this." 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. USB drives are also compatible with older USB 1.1 ports, but speeds are much slower.

Current operating systems recognize USB drives without needing special drivers. The simplest USB flash drives show up as a drive letter on your computer; you can simply drag and drop files to the drive. 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 like 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.