This post was published 3 years 4 months 22 days ago. This info might have changed or might have become outdated.

There are so many choices out there that often it is a "grab and see if it works" routine that you follow. Often you get a new card based on previous experience or a reccomendation from a friend.

Sam White from Trusted Reviews has a long, well presented review on memory cards that you might want to read. There are so many choices, all with variables that can and do have an effect on what you can accomplish.

Part of what Sam had to say follows:

Testing flash memory cards is not as straightforward as one might think. There are many factors that can affect performance ranging from the type of data that is recorded or copied (and its directory structure), the flash memory chips used, the performance and compatibility of the card’s onboard controller and of course, how well these operate with the card reader and camera that you use. These varying factors and host devices make it very difficult to control and standardise the tests, and will invariably introduce bottlenecks into the equation.

In this respect, you’ll find that most manufacturers quote read and write speeds obtained from tests under ideal conditions where “real world” bottlenecks have been minimised. One of the most popular providers of tests and testing equipment is TestMetrix. The equipment they design and manufacture is geared toward getting the most out of memory cards and as such can reveal their true read and write potential.

For you, and me it’s probably best to regard this as compliance testing so that memory manufacturers can meet the standards set by the CompactFlash, Secure Digital and MultiMediaCard Associations, thereby allowing them to adorn their cards with figures like 20MB/sec and 133X.

I think you will like what Sam did. It is long but it is good. You will learn a lot! Read Sam’s article "Memory Card Roundup" here.