Choosing the Right Memory Card: A Comprehensive Review of SD Card Formats and Classes

This article provides a comprehensive review of SD card formats and classes to help you make an informed decision. From SDHC to microSDXC, we’ll explore the differences between various formats and their compatibility with different devices. Dive deep into understanding SD card classes and their impact on read and write speeds, essential for capturing high-quality photos and videos. Whether you’re a photographer, videographer, or simply looking to expand your device’s storage capacity, this guide will equip you with the knowledge to select the perfect memory card for your needs.

Choosing the Right Memory Card: A Comprehensive Review of SD Card Formats and Classes

In this article we would like to have a look at the most frequently asked questions regarding SD cards and choice of cards for various gadgets – a tablet, a camera, a video camera or a phone. We believe this information will be useful for the wide range of our readers.

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Memory card dimensions

Memory cards are produced in three types of dimensions:

  • MicroSD: a very popular card type used in smart phones, tablets and other portable devices. The dimensions are 11x15mm;
  • MiniSD: a less popular card type often met in mp3 players. The dimensions are 21,5x20mm;
  • SD: probably the most popular one used in cameras, video cameras, recording units and other devices. Almost all modern laptops and computers are equipped with card readers that work with this card type. The dimensions are 32x24mm.
Memory cards types

Important notice! In spite of having an adapter supplied together with, for example, a MicroSD card, it is not recommended to use this set of two devices instead of a regular SD card. The matter is that MicroSD cards are usually slower than SD cards which means that a MicroSD card connected to a video camera through an adapter cannot be used to record video in Full HD. That is why the card type should be selected in accordance with requirements of your device manufacturer.

MicroSD adapter

Speed or class of SD cards

This is a very important parameter for any memory card. It is because speed influences not only the price but also the range of devices where such card can be used.

The speed characteristics of a memory card are usually marked by a rating and/or a digit that shows you memory card class. Ratings correspond with the Read mode speed. The Write mode speed is usually two or more times lower and it is determined by the card class.

Classes of SD cards

By the way, rating and card class are interrelated.

Rating and card class

Manufacturers may use different ways to mark their cards. For example, the picture below shows a Class 4 memory card – according to the table above, its speed is 4 MB/s.

Memory card (class 4)

Some manufacturers also specify the speed in addition to the class.

I would like to point to one more detail again. When buying a memory card make sure you know what class your device requires for normal operation.

Memory card generations

There are four generation of memory cards:

  • SD 1.0 — from 8 MB to 2 GB;
  • SD 1.1 — up to 4 GB;
  • SDHC — up to 32 GB;
  • SDXC — up to 2 TB.

They differ in capacity, speed and are backward-compatible with each other.

There is an important aspect, though: A device that can read SDHC cards, will read SD 1.1 and SD 1.0 cards as well, but will not “see” a SDXC card.

How to check the real capacity and class of a memory card

Sometimes there are no symbols or letters on a memory card, so you don’t know its real capacity or class without testing. Luckily, there are a lot of special utilities to test memory cards.

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Choosing a memory card for a tablet PC

In the present-day market, most tablets feature built-in memory and support memory cards. Yes, there are still tablets supporting SDHC cards (up to 32 GB), but they are not too numerous, and most tablets work with SDXC cards.

If you’re not going to record HD video (or you have a low definition camera) then your tablet will work correctly even with a Class 4 card. However, if you have plans for videos, I recommend choosing a Class 6 or Class 10 memory card. As a rule, the real difference between Class 6 and 10 performances is not so big to pay more.

Choosing a memory card for a camera/video camera

In this case, you should be more careful. The matter is that if you use a memory card of a class lower than required by the device it may work with some problems, and you can forget about recording good quality videos.

Finally, some advice for you: go to your camera manufacturer’s official website and find the user manual there. In the manual, there must be a page entitled Recommended memory cards (i.е. SD cards that the manufacturer has tested!).

When choosing a memory card pay attention to the manufacturer. We are not going to choose the best from the best now but we recommend buying cards by well-known brands only.

Using memory cards with characteristics recommended by device manufacturers and produced by well-known brands that take care of their reputations and the quality of their products will secure you from many possible issues. These can include instable work of your device and the subsequent risk of losing important data from the memory card.

The tool recovers data from any devices, regardless of the cause of data loss.

If you need to recover data from memory cards in FAT file system, we recommend using Hetman FAT Recovery. If your memory card is managed by a different file system, files in any format can be restored with the help Hetman Partition Recovery.

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Vladimir Artiukh

Author: , Technical Writer

Vladimir Artiukh is a technical writer for Hetman Software, as well as the voice and face of their English-speaking YouTube channel, Hetman Software: Data Recovery for Windows. He handles tutorials, how-tos, and detailed reviews on how the company’s tools work with all kinds of data storage devices.

Oleg Afonin

Editor: , Technical Writer

Oleg Afonin is an expert in mobile forensics, data recovery and computer systems. He often attends large data security conferences, and writes several blogs for such resources as, Elcomsoft and Habr. In addition to his online activities, Oleg’s articles are also published in professional magazines. Also, Oleg Afonin is the co-author of a well-known book, Mobile Forensics - Advanced Investigative Strategies.

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