Not all memory cards are created equal, and it's easy to get confused when faced with the alphanumeric soup of specs splashed all over SD card packaging, all claiming to be the fastest and the best. Well help is on the way. The SD Association has just announced two new symbols to help consumers choose the best SD memory cards for their specific needs and devices.
The symbols identify high-speed performance standards for SDXC and SDHC memory cards and devices: The UHS-I symbol (a bold capital letter I) is for products with bus interface speeds up to 104 Megabytes per second (which is four times the existing 25 Mb/sec speed maximum) , and a new UHS Speed Class 1 symbol (a number 1 nestled inside a letter U) is for UHS-I cards and products that include a performance option to designed to support real-time video recording.
While the new Speed Class 1 symbol will only appear on UHS-I SDXC and SDHC products, note that the existing Speed Class symbols (Class 2, 4, 6, and 10) are for non-UHS SD, SDHC, and SDXC products and refer to the minimum write speed performance of the cards.
Memory cards and devices that sport the new symbols are backward compatible (so you can still use older SD cards in the newest devices, or use new UHS-I memory cards in old devices) but as you'd expect, you'll get the maximum performance with UHS-I products if both your memory card and your device (digital camera, camcorder, etc.) support the standard. The new symbols allow consumers to match symbols as they shop for cards or devices and achieve the most benefit when they are paired up.
The SD Association was founded in 2000 by Panasonic, SanDisk, and Toshiba to set industry standards and promote SD products, and currently has about 1,000 members.