commentary While Secure Digital (SD) memory cards are physically getting smaller, with miniSD and microSD quickly becoming a popular choice for mobile phones and MP3 players, the capacity of the regular postage-stamp sized SD cards has just taken a leap.
Currently, SD cards max out at 2GB. A new memory specification from the SD Card Association (SDA 2.0) allows for cards from 4GB to 32GB, identical in shape to their predecessors.
Due to a different file system used by the new SD High Capacity (SDHC) cards, they aren't recognisable by legacy SD devices, so you won't be able to use them in existing cameras. So far, we've only heard of a couple of cameras that are SDHC-compliant, such as the upcoming Panasonic Lumix L1. Existing SD cards (2GB and under) will continue to work in the newer devices.
Memory maker SanDisk, which hopes to release 4GB SDHC cards bundled with a USB 2.0 reader locally by the end of the year, urges consumers to be aware of high-capacity non-SDA 2.0 cards hitting the market. According to SanDisk, data corruption can occur when non-compliant 4GB SD cards are swapped between SDHC and SD devices, and older cameras may only see these cards as having 2GB of storage. Toshiba and Panasonic have also announced plans to release 4GB cards internationally.
Part of the new SD specification includes classifications of data transfer speed. So a Class 2 card will have a minimum transfer speed of 2MB/sec, 4MB/sec for a Class 4 card, and 6MB/sec for a Class 6 cards. Again, to get any kind of benefit from using Class 4 or 6 cards, you'll need a device that supports data transfers at these rates.
4GB cards can store around 2,000 high-resolution pictures, more than 1,000 digital songs or up to 8 hours of MPEG4 video.
Do you have any need for a 4GB SD card? How about a 32GB one? Is the type of memory card important? Are Sony Cyber-shot or Olympus cameras less appealing with their proprietary formats (Memory Stick and xD)? Send your thoughts to firstname.lastname@example.org or leave your comment below.