How do I check the class of a micro sd card? I'm thinking about getting a new sd card and read that the class of them really matters. I'm looking at getting a 16gb one with a class not less than class 6. How do I check for the class?
An SD Card class basically the minimum sequential write speed that the SD card supports. Testing the class of an SD is quite easy, just copy a 1 GB file to an empty card and measure the time it took for the copy. A class 6 SD card should support at minimum 6MB/s. 

Also check out the markings on the SD card, there should a logo like the following:



the number in the logo describes the speed class.