If you use a smartphone, then in all probability you are not a stranger to microSD cards. SD is an abbreviation of the term “Secure Digital”. At the moment, microSD cards are the smallest commercially available memory cards.

Inspite of their tiny size, microSD cards do pack a wallop, with 8GB and 16GB cards being available. Cards with smaller disk space are available too – 512MB, 1GB, 2GB, and 4GB. But unknown to lots of people, these cards are not only about disk size. Perhaps you have seen different retailers offer cards of the same disk size at significant costs, and naturally just went for the cheaper option?

Well, you might be shooting yoursef in the foot. You see, microSD cards are rated by class. As such, you can have two 4GB cards with two different ratings, and one will perform better than the other. In some cases, some smartphones’ performances are impacted if you use a lower rated microSD card than it requires.

MicroSD Card Ratings

• Class 2 -speed of 2 MB/s or higher is guaranteed at the best fragmented state where no memory unit is occupied
• Class 4 – speed of 4 MB/s or higher is guaranteed at the best fragmented state where no memory unit is occupied
• Class 6 – speed of 6 MB/s or higher is guaranteed at the best fragmented state where no memory unit is occupied
• Class 10 – speed of 10 MB/s or higher is guaranteed at the best fragmented state where no memory unit is occupied

For example, if you have a smartphone that does full HD video recording, you are better off with a card rated Class 4 or above.

Be sure that you know what the requirements of the device that you will be using a microSD card with, and check the card for a rating before buying. For many of today’s smartphones, I recommend that you do not use a card rated below Class 4. Not worth it.

Take a look at the close-up picture to the right. See the circled figure that the red arrow points to? That’s the rating of that card. That card is a Class 4 card. Not all manufacturers provide this information on their cards. Of course, if they don’t you have no way of knowing.

As a rule, purchase microSD cards made by reputable manufacturers. One well known brand is SanDisk. If possible, avoid nameless cards.

Conclusion
Why should you care? Because it matters. Some of the complaints about some smartphones freezing up or hanging stem from the user putting in lower rated cards. Because the device requires something faster, each time info is to be accessed or lodged in the card, the device stutters, freezes or slows down significantly.

Video recording and/or viewing is another case, especially high definition video. Higher rated cards guarantee you good quality recording and smoother playback.

Now you know.

Okay, this is getting wierder by the day. Now, we are convinced that the Microsoft guys working on Windowsphone 7 Series slept and woke up waaaay back in 1980 or thereabouts.

How else do you explain all the features that are being excluded from Wp7S? First, it was multi-tasking, then copy and paste, and now removable memory. No microSD? No MiniSD? No cards at all.

Yes; we want to scream. But what’s that going to achieve?

Source. Incidentally, we notice that Afewgoodmen mentioned this in a recent comment he made on another article we published recently on Windowsphone 7 Series.