Monday, February 9, 2009

The X Factor

Let’s separate some fact from fiction when it comes to memory-card speed.
By Kim Castleberry Published in Accessories
The X Factor

It used to be that a small group of people, such as pro photographers, needed high-speed cards. But as manufacturers develop higher-resolution cameras, file sizes are growing larger and therefore taking longer to record to a memory card. Using a high-megapixel camera with a standard-speed card creates a lag time between shots because of a slow write speed and lengthy download times to your computer because of a slow read speed.

CompactFlash and Secure Digital are the memory-card formats typically categorized by the x factor. Secure Digital High Capacity (SDHC) speed class ratings are standardized and more objective. All SDHC cards that are Class 4, for example, can write at the speed of 4 MBps. Class 6 cards write at a minimum of 6 MBps.

ATP ProMax II CompactFlash cards ( deliver read speeds of up to 45 MBps and write times of up to 30 MBps. The cards are UDMA-compliant and have capacities of up to 16 GB. Estimated Street Price: $185 (8 GB).

Kingston’s 32 GB Elite Pro SDHC memory card ( has a Class 4 speed rating and is particularly useful for shooting high-definition video. Estimated Street Price: $247.

Lexar ( has upgraded several of its cards, including the UDMA-compliant Professional 300x 16 GB CompactFlash card featuring a 45 MBps write speed. The Professional 233x CompactFlash cards come in 2, 4 and 8 GB capacities with 35 MBps read/write times. Estimated Street Price: $359 (16 GB CF).

The PNY 16 GB Class 6 Optima Pro SDHC card ( has a 6 MBps transfer rate, ideal for high-megapixel cameras and demanding camcorders. Estimated Street Price: $119.

With a 30 MBps transfer rate, the SanDisk Extreme III 32 GB CompactFlash card ( doesn’t sacrifice speed for capacity. Estimated Street Price: $199.

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  • Comment Link Maureen Thursday, March 5, 2009 posted by Maureen

    Thanks very much for the "complete" explanation in plain English. I appreciate it.

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