Fundamental Differences of SDHC and SDXC

The SDHC and SDXC cards are an evolution of our beloved SD card technology. This is basically concerned with the Secure Digital Format of data storage. The term SD is only due to the format associated with it, the Secured Digital Format. There are a number of devices out there that support these small storage cards. Let us dig into the fundamental difference between SDHC and SDXC memory cards.

The use of these memory cards is a result of the constant need of data storage space. Another factor that enhances its requirements is the demand for high-speed transfer. That would be due to the devices they are used in. Most of these cards have their utilization in high-quality imaging devices such as Cam-coders, Digital Camera, Mobile phones etc. most of the times, the device needs a high speed of reading and write cycles. The memory cards are specially designed to meet the speed needs of these devices.

In our further discussion about these SDHC and SDXC cards, you will discover some interesting facts about these cards and their possible implementation. About the implementation of various devices and their speed limits. Further, you will learn about different classes of the SD cards and other differences of SDHC and SDXC cards.

What is SDHC and SDXC memory card?

As mentioned earlier, the evolution of classic SD cards gives rise to the designing of SDHC and then SDXC cards. There is always an increasing demand for high efficiency and high capacity in a small memory card.

So as the demand for higher capacity grows, the SD started evolving and thus came the SDHC card. The SDHC is a high capacity SD card and has a much higher capacity to save information. SDHC stands for Secure Digital High Capacity memory cards.

For the devices with more necessity for storage space, the SDXC memory card is designed. These cards have a much higher capacity than the conventional SD card and also SDHC cards. SDXC stands for Secure Digital Extended Storage memory cards. These memory cards have extended storage space and are highly efficient.

Capacity of SDHC and SDXC

The capacity of a conventional SD card was from a few MBs to 1 or 2 GBs. They were used in some of the digital cameras and other imaging devices. The SD cards had also their implementation in small electronics.

But the SDHC cards exceeded it with a capacity of around 4GB to 32 GB of memory space. Most of the modern electronics need a memory capacity of somewhere around this range. Most of the DSLR cameras and small electronic devices use the SDHC cards.

The higher necessity of memory space gives rise to the demand of a larger memory SD card. The SDXC card is the solution for the extended capacity need. These cards have a storage space of more than 32GB, it is the higher limit of an SDHC memory card. The upper limit for the memory capacity of the SDXC card is said to be 2TB.


The memory cards are compatible with their contemporary developed devices. And the cards come with a backward compatibility concept.

Suppose you have a device that supports the SD card, it means that you can’t use SDHC or SDXC cards in that device. If the device is compatible with SDHC card, you can use SDHC and the old SD card. And for the device with SDXC compatibility, you can use SDXC, SDHC card, and SD card in the device.

Using an incompatible storage card in the device may result in many issues. Your memory card can experience a huge data loss. In such case, you have to go through a different procedure to get all your data back. You may have to use relevant software to recover data from SDHC on mac, Windows etc.


The memory cards have a significant difference in their performance. They are designed to meet the requirements of their contemporary electronics. That means the speed requirement is way apart than each other.

These cards come in different classes, these are the speed classes of an individual memory card. They have a class rating from 2 to 10. Which defines their effectiveness and speed during the read-write cycle. A minimum speed of data transfer is defined by these speed classes.

A class 2 SDHC memory card will have a transfer rate of around 2 MBPS. As the class goes high, the speed becomes higher. At the highest level of rating which is a class 10 memory card. For a class 10 SDHC card, the transfer rate would be 10MBPS.

The compatibility of this memory cards depends upon the purpose and device used in. some of the high-class memory cards have a significant performance with a specific device.

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John Harris

Senior Editor, Content Analyst and a fan of exceptional customer service. John develops and publishes instructional and informational content regarding partition management, Windows hot-fixes, data management and computer troubleshooting.

As a tenured data recovery specialist, John shares exceptional insights and blog posts about data loss and data recovery across any storage device. With 8+ years’ experience in writing for Data Recovery for both Mac OS and Windows OS computers, he is an avid learner who always wants to polish and simplify the data recovery process. John passes his free time playing Chess and reading Science Fiction novels.

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