www.thinkingsoul.in : Tech feeds for the hungry souls!

Buying a SD Memory Card

So, which all parameters do you think the most critical when buying a SD memory card?  Most of us feel that the Brand and the memory capacity are the only 2 important things to make the buying decision. Unfortunately, this is not true.

What to look out for?

In addition to the brand and the memory capacity, there exist 2 more parameters which play a very crucial role in determining the correct SD card for your use. Like any other media, SD cards vary in their read/write speed which is very important when capturing audio or video. The read/write speed of the SD memory card is expressed in 2 ways:

1. Speed Class

Class of the SD memory card identifies its minimum write speed. As of now, SD card comes in four different classes: Class 2, Class 4, Class 6 and Class 10. Thus, a class 2 SD card can write data at minimum speed of 2 MB/s. Remember, the class identifies the minimum speed and not the actual rate at which the data can be written. Thus, a class 2 SD card can write data at a speed of 15 MB/s also, but not less than 2 MB/s.

chart Buying a SD Memory CardSDultraII32GB Buying a SD Memory Card


2. Commercial X Rating

This is comparatively an older way of expressing the memory card speed (such as 100x, 200x, etc.). In X rating technique, 1X is equivalent to the initial standard CD-ROM speed of 150 KB/s. Remember, X rating speed determines the maximum data transfer rate of the memory card.

memory speed Buying a SD Memory Card


Happy shopping!






Author, blogger and technology enthusiast. Omkar is the founder and the editor at ThinkingSoul.in. To know more about him, you may visit his personal blog at www.omkarvpatil.com or .


  1. Nishant Patel says:


    does the number is mentioned on every company memory card?

  2. Omkar Patil says:

    Yes Nishant. Speed class rating standard is accepted by the SD Association(www.sdcard.org) and thus all SD card manufacturers will have to print the SD speed class rating symbol on the card.

  3. Nachiket Bhingade says:

    Really helpfull article.. Very Nice.

  4. priyanka says:

    Nice Tip while buying SD Card…

Leave a Comment


— required *

— required *