Flash Memory Buying Guide

Buying Flash Memory

Does anybody remember floppy disks? The rise in popularity of flash memory has relegated disks to the scrap heap along with LPs and eight-track tapes. Flash memory is the de facto portable storage medium, used in cameras, phones and other portable (and not so portable) devices. Buying flash memory means finding and matching the type of memory you need with the speed and capacity to get the job done right.

Know Your Type

Flash memory comes in a number of different forms, each with its own uses. Here are some of the most popular types:

Compact Flash. Compact flash memory devices have been around for a while, but still have a large share of the high-end digital camera market. The large storage capacity (up to 32GB) and high access speed (as high as 600X!) make Compact Flash memory devices perfect for large, high definition image files.

Secure Digital. The most popular form of flash memory for portable devices, Secure Digital flash memory comes in three size formats: standard (used in printers and cameras) miniSD (used in cameras and other devices) and microSD (used in cell phones and GPS devices). The smaller formats are often sold with adapters for use with other devices.

Memory Stick. This proprietary format is used in Sony cameras and other devices. The original Memory Stick was replaced by the Memory Stick Pro, which provided faster read times and larger storage capacity. Many third party vendors produce Memory Stick/Pro flash memory units for use with Sony devices.

USB. Most frequently used as a floppy disk replacement, USB disks have storage capacity of up to 256GB. USB drives are used with personal computers, game consoles and some home theater media players.

Understanding Capacity

You can never be too thin, too rich or have too big a flash memory device! Determining your capacity needs is a matter of what you'll be storing and the size of your library. The following are some ballpark ideas of how capacity relates to the storage of various media:

Music. Assuming a bit rate of 128bps and an average four minute song length, you can expect to be able to store about 250 songs per 1GB of flash memory storage.

Video. Video compression, bit rate and other factors vary wildly from video file to video file, but generally you can expect to store about 24 minutes of DVD quality video per 1GB of flash memory storage—just about the length of a half hour sitcom without commercials.

Images. Using a 5-megapixel image stored in JPEG format, you can expect to store about 360 images on a 1GB flash memory device.

Reading Specifications

Flash memory devices are rated in terms of capacity and speed. Obviously, capacity is important, depending on the size or number of files you plan to store. Speed is also a factor, however, especially with high-resolution images or videos files.

Capacity is expressed in megabytes (MB) or gigabytes (GB). Gigabytes are the larger units of storage and are more commonly seen in contemporary flash memory devices.

Speed is expressed using an “X” measurement, where X equals 150 Kilobytes per second. The speed reference is for file transfers to and from the device. Some examples of speed measurements are 10X (1.5 MB per second) and 200x (3GB per second).

Need to know more?

• Flash Memory
  http://www.prontotech.com/flash-memory
• PC World: Flash Memory Cards
  http://www.pcworld.idg.com.au/article/193902/flash_memory_cards/
• Flash Memory Card Buying Guide
  http://www.newegg.com/product/CategoryIntelligenceArticle.aspx?articleId=220