Confused about Flash Memory?

Flash memory cards are those tiny little cards that go inside your digital camera, cell phone, MP3 player or digital video camera. Most cards have have plastic casings, but some cards have steel casings with labels over the steel casings.

There seems to be a lot of confusion as to what these cards are called, which cards go in which device, etc. I will try to address some of the commonly asked questions about flash memory cards in this blog entry.

What is Flash Memory?
Flash memory refers to the chips inside the flash memory cards that store the digital signals that make up your digital photos, songs or videos. Some flash memory card have one chip inside. Some cards have multiple chips inside so that your card can have more memory, in the form of megabytes (MB) or gigabytes.

How do I choose the right card for my device?
Card Form Factors or Different Types of Cards
First you have to choose the right "form factor." The card's form factor refers to the shape and physical size of the card. Different card form factors have different names. The most popular form factor is the Secure Digital card (SD Card for short). Other popular card form factors include the CompactFlash card (mostly for big digital cameras) and the Memory Stick Pro Duo card (mostly for Sony devices). Another card that is the same shape of the SD card is the SDHC card. The SDHC card has higher capacities than the SD card. This brings us to the thing to consider when choosing a flash memory card, capacity.

Card Capacity
A card's capacity is the primary factor in determining the amount of pictures, music or videos your flash memory card can store. It is often expressed in the form of megabytes (e.g., 256MG, 512MG) or gigabytes (e.g., 1GB, 2GB, 4GB, 8GB, 16GB). Devices nowadays require cards in the gigabyte range to be useful. To determine how many gigabytes you'll need, look in device's manual to see how much one 1GB of memory will hold. For example, in some cameras, 1GB might allow you to store 500 pictures. In another camera, it might allow you to sore only 50 pictures.

Card Speed
If you are going to use really big cards for things like videos or hard drive back up, speed will be important. Most card makers that care about card speed often express the speed in "x" increments, like 50x, 133x or 266x. The higher the "x" number, the better. 1x equals a transfer speed of 150KB per second. So, a 100x card would allow you to transfer 15000KB/s or 15MB per second onto the card or off the card. When you are taking a picture with your camera and your camera is storing the picture on the card, we say that it is writing the data for the picture on to the card. So a faster card would allow your camera to store your photos faster to so that you can take the next picture. When you are done taking pictures and you want to copy those gigabytes of photos to your computer, you will want to read the photo data from your cards and save them onto your computer. In this case, the fast read speed of your card will allow you to transfer your photos faster.

Other Card Form Factors
Other less common card form factors include xD Picture cards (used mainly in Fuji cameras), microSD cards (used mainly in cell phones), M2 cards (used mainly in Sony-Ericson cell phones), PC Card, ExpressCard, SxS Card, P2 Card, SmartMedia, MMC, miniSD, and the list goes on. These are less common. And if your device uses one of these cards, your manual will say which card it uses.

USB Flash Drives
USB Flash Drives (Flash Drive for short), also called keychain drives, thumb drives, or sadly memory sticks, have the same flash chips as those found in flash memory cards. These USB Flash Drives are designed so that one end of the device plugs easily into the USB port found on most modern computers. These USB flash drives allow you to carry your import documents on your keychains, around your neck, in your pocket or in any other manner you choose because they are so tiny. People often call them thumb drives because they are no bigger than your thumb. Yet they have the potential help you move hundreds or even thousands of songs, pictures, essays or video clips from one computer to another.