SDHC vs SDXC – Understanding Camera Card Differences

The world of digital photography is filled with a range of equipment and accessories, each serving a unique purpose. Among these, SD cards, specifically SDHC and SDXC, play a crucial role in how we store and manage our data. They may look similar in appearance, but their capabilities, compatibility, and suitability can vary greatly, depending on your specific requirements.

A Brief Overview of SDHC and SDXC

Basic Details of SDHC

SDHC, or Secure Digital High Capacity, was launched in 2006 as a much-needed upgrade to the then prevalent SD cards. With the capacity to store anywhere from 4GB to 32GB of data, SDHC cards were aimed at serving devices that had a moderate need for storage. These cards adopted the FAT32 file system, an improvement from the earlier used FAT16. However, FAT32 limits the maximum size of an individual file to 4GB, which could potentially cause issues when dealing with larger files. Despite this limitation, SDHC cards quickly gained traction and became ubiquitous in a broad spectrum of devices. They were especially popular in older and entry-level cameras that did not require massive storage. Today, SDHC cards continue to be a practical choice for devices with moderate storage needs.

Basic Details of SDXC

The introduction of SDXC (Secure Digital Extended Capacity) cards in 2009 marked a significant advancement in digital storage technology. With a storage range that starts from 64GB and extends up to an impressive 2TB, SDXC cards have left their SDHC counterparts far behind in terms of capacity. They utilize the exFAT file system, which lifts the 4GB file size limit imposed by the FAT32 system used by SDHC cards. This means SDXC cards can handle significantly larger individual files, making them ideal for today’s high-resolution cameras and video recording equipment. The large storage and superior file handling capability have led to the widespread adoption of SDXC cards in high-performance devices, where professional photographers and videographers can tap into their immense capacity and speed.

Shared Characteristics

  • Physical Attributes : One of the key commonalities between SDHC and SDXC cards is their physical dimensions. They both share the same length of 32mm and a width of 24mm, seamlessly fitting into the standardized SD card slot. This identical size is a thoughtful design feature rather than a mere coincidence, facilitating seamless swapping of these cards across a diverse array of devices. Whether you are using a digital camera, a video recorder, a laptop, or any other portable gadget, you can rely on these cards for memory expansion due to their compatible size. This universal sizing not only simplifies the user experience by offering compatibility and interchangeability, but also provides users with flexible storage options. You can choose between SDHC and SDXC cards based on storage needs without worrying about physical compatibility.

  • Speed Classes : Speed Classes are an integral characteristic of both SDHC and SDXC cards, acting as a guarantee for minimum data transfer speeds. These cards can be categorized under several speed classes, including Class 2 (guaranteeing a minimum write speed of 2MB/s), Class 4 (4MB/s), Class 6 (6MB/s), and Class 10 (10MB/s). These speed classes are the bedrock of the cards’ performance, underpinning their ability to handle various tasks with different data intensity levels. The SDHC and SDXC cards aren’t confined to these base classes, as they can also be assigned to the Ultra High Speed (UHS) classes of U1 and U3, signifying minimum write speeds of 10MB/s and 30MB/s respectively. These speed class designations are particularly crucial when the cards are used for tasks such as video recording that requires a constant and reliable data writing speed.

  • Bus Interface : The Bus Interface is a shared feature between SDHC and SDXC cards. Specifically, they both accommodate the UHS (Ultra High Speed) bus interfaces – UHS-I and UHS-II. These UHS standards dictate the theoretical maximum transfer rates. UHS-I supports speeds up to 104 MB/s, providing a significant performance boost for high-speed data transfer. UHS-II goes further, supporting potential transfer rates as high as 312 MB/s, enabling even more intensive data tasks. However, these speeds are not a guarantee but rather the maximum potential performance. To fully realize these speeds, the device used with the card must also support the corresponding UHS standard. If a device doesn’t match the card’s UHS standard, the card will operate at the highest speed the device can handle. Therefore, matching the UHS standard on both the card and device is essential to maximize performance.

  • Write-Protection Mechanism : Both SDHC and SDXC cards come with a write-protection switch, typically located on the card’s side. This feature is a preventative measure designed to ward off unintended data loss. When users activate the write-protection switch, it forbids any new data from being written onto the card, and similarly, it stops any existing data from being erased or overwritten. This feature can prove to be a lifeline in scenarios where you need to protect the data already stored on your card from accidental modifications or deletions. To enable writing or erasing of data, you must toggle the switch off. Thus, both SDHC and SDXC cards provide a straightforward yet potent method for data protection. This added security layer gives users peace of mind, knowing their precious data is safe from accidental changes or losses.

Key Differences

  • Storage Capacity : A central distinction between SDHC and SDXC cards lies in their storage capacity. SDHC cards, being the earlier iteration, offer a storage range from 4GB to 32GB. While this might seem limited compared to today’s standards, it provides adequate storage for many users, especially those utilizing older or entry-level devices. These devices typically do not generate large file sizes, and hence a SDHC card’s capacity is often sufficient. However, in contrast, SDXC cards represent a leap forward in digital storage, offering vastly superior capacities that range from 64GB up to a colossal 2TB. The emergence of SDXC cards was a game changer, catering to high-performance devices and professional applications, where the generation of large files – such as high-resolution photos, 4K or 8K videos – is commonplace. Therefore, for users whose needs exceed the 32GB limit of SDHC cards, SDXC cards are the natural choice, providing ample room for expansive file collections.

  • File System : Another point of divergence between SDHC and SDXC cards is the file system each uses. SDHC cards operate on the FAT32 file system, which, while reliable, imposes a maximum individual file size restriction of 4GB. This restriction can be a bottleneck when recording long, high-resolution videos or working with large data files that can easily surpass this limit. Contrastingly, SDXC cards employ the exFAT file system, which eliminates the file size constraints associated with FAT32. The exFAT system can handle significantly larger individual files, virtually without any upper limit. This characteristic makes SDXC cards particularly appealing for professionals who regularly work with high-definition multimedia files, such as 4K or 8K videos. With an SDXC card, they can record longer videos without worrying about the 4GB file size cap.

  • Device Compatibility : While both SDHC and SDXC cards boast extensive device compatibility, it’s essential to note that not all devices can accommodate both types of cards. The majority of modern devices are engineered to support both SDHC and SDXC cards, offering flexibility in terms of storage options. However, certain older devices or models can only support SDHC cards due to their hardware limitations or software restrictions. Before purchasing an SDXC card, it’s crucial to check your device’s specifications to confirm its compatibility with this format. Investing in an SDXC card for a device that only supports SDHC can result in wasted resources and frustration. Therefore, understanding your device’s compatibility is key to selecting the right memory card and getting the most out of your device’s performance.

  • Cost : Cost considerations also distinguish SDHC from SDXC cards. Given their lower storage capacities and older technology, SDHC cards are generally less expensive than SDXC cards. Therefore, they can be a cost-effective choice for users with less intensive data needs. Conversely, SDXC cards, with their larger capacities and more advanced technology, tend to be pricier. While they offer higher performance, they might not be cost-effective for users with moderate storage needs.

Suitable Scenarios for SDHC

SDHC cards, characterized by their maximum storage capacity of 32GB and the usage of the FAT32 file system, serve as a pragmatic choice in various scenarios. Specifically, if you have an older model camera or a device that doesn’t necessitate gargantuan storage space, such as entry-level DSLRs or compact digital cameras, an SDHC card would be the perfect complement. Thanks to their ample storage capacity, these cards can effortlessly manage a decent volume of lower-resolution images and standard definition videos.

Moreover, if you fall into the category of casual photographers or hobbyists who don’t need to store substantial quantities of high-resolution photos or high-definition videos, an SDHC card should meet your needs comfortably. The storage offered by these cards provides a balance between capacity and cost, making them a viable option for those who don’t need the extensive storage of an SDXC card.

Additionally, for users on a budget, SDHC cards offer an ideal solution. They are typically cheaper than SDXC cards, making them a sensible choice for those wanting to balance performance with cost-effectiveness. In essence, SDHC cards offer a practical balance between storage capacity, compatibility, and cost, making them a reliable choice for a broad user base.

Suitable Scenarios for SDXC

On the other end of the spectrum, SDXC cards, defined by their expansive storage range and exFAT file system, find their niche in situations necessitating the handling of voluminous and large files.

For professional photographers and videographers, SDXC cards are the preferred choice. Their ability to store a high volume of high-resolution images and 4K or 8K videos makes them indispensable in professional fields. Furthermore, they cater perfectly to high-end DSLR and mirrorless cameras, which are designed to produce large file sizes to maintain image and video quality.

For those passionate about their photography and frequently shooting in RAW format, an SDXC card’s higher capacity proves to be a major advantage. RAW format captures all image data from the camera sensor, resulting in large files that deliver superior quality and editing flexibility.

However, these advantages come with a higher price tag. The advanced features and superior storage capacities of SDXC cards make them more expensive than SDHC cards. Therefore, while the investment is justified for professionals and serious enthusiasts, casual users may find SDHC cards more suited to their needs and budget.

Which One is Superior? SDHC or SDXC?

When discussing the superiority of SDHC or SDXC, it’s important to consider that the superiority of one over the other is not universal, but highly contextual. The “better” choice is dictated by the specific requirements, budget, and device compatibility of the user.

In scenarios where you are capturing high-resolution photographs, recording 4K or 8K videos, or dealing with extensive data files, the SDXC card naturally comes out on top. Its substantial storage range, starting from 64GB and extending up to a mammoth 2TB, coupled with the exFAT file system’s ability to manage exceptionally large individual files, makes it an unrivaled choice. For professional photographers, videographers, or anyone working with data-intensive tasks, the SDXC card stands as the superior option, providing both the capacity and speed needed for such demanding applications.

Contrastingly, for users whose devices do not support the SDXC format or whose data needs are more modest, the SDHC card is not only adequate but may indeed be the superior choice. With storage capacities ranging from 4GB to 32GB and using the FAT32 file system, it caters perfectly to less data-intensive tasks such as storing standard resolution photos and videos. It’s also worth noting that SDHC cards enjoy broader compatibility with a range of devices, including older models that may not support the SDXC format. Furthermore, from a cost perspective, SDHC cards are typically less expensive than their SDXC counterparts, making them an appealing choice for users on a budget or those who don’t require the extensive storage provided by SDXC cards.

Thus, in determining superiority between SDHC and SDXC, the individual needs, device capabilities, and budget considerations of the user play a pivotal role. Neither card is inherently superior, but each excels in meeting specific user needs and scenarios.

Conclusion and Final Recommendations

SDHC and SDXC, while similar in appearance and fundamental function, are distinct in their capabilities and are designed to cater to different user requirements. The choice between the two extends beyond mere brand selection and delves into the realms of understanding your specific storage needs, the nature of the media you’re handling, the compatibility of your device, and of course, your allocated budget.

If your pursuits involve the storage of hefty files such as high-resolution photos, 4K or 8K videos, and if your device supports it, the SDXC card is the optimum choice. Its higher storage capacities and the ability to manage larger individual files with the exFAT file system make it ideal for such demanding tasks. The SDXC card is, in essence, a future-proof investment for those aiming for high-end performance.

Conversely, if your device is an older model or if your photography or videography endeavors mainly involve lower-resolution images and videos, an SDHC card would serve your purpose effectively. With its wide compatibility range, lower price point, and sufficient storage capacity for less demanding tasks, an SDHC card offers a balance between cost and performance.

The crux of the matter lies in understanding the differences between SDHC and SDXC and aligning these with your specific needs and resources. Ensuring that you cross-verify the specifications of your device before making a purchase is crucial to ensuring maximum compatibility and performance. The right choice of card, whether SDHC or SDXC, will go a long way in enhancing your photography or videography experience, making it seamless and efficient.


What SD card do professional photographers use?

Professional photographers typically use SDXC cards due to their substantial storage capacities, ranging from 64GB to 2TB, and the ability to handle large individual files thanks to the exFAT file system. These features are crucial for high-resolution photos and 4K or 8K videos common in professional photography. Also, they often opt for cards with higher speed classes such as UHS-I U3, UHS-II, or UHS-III, which offer faster data transfer rates, thereby reducing the time taken to save and access files, a critical factor in high-paced professional settings.

What is the difference between UHS and U on SD card?

The terms UHS (Ultra High Speed) and ‘U’ on SD cards pertain to different aspects of the card’s performance. UHS refers to the bus interface — the data transfer path that connects the card to the device. There are two UHS types: UHS-I and UHS-II, each offering progressively faster data transfer rates. UHS-I offers speeds up to 104MB/s and UHS-II up to 312MB/s.

On the other hand, the ‘U’ symbol, which is usually followed by a ‘1’ or ‘3’ (U1 or U3), refers to the card’s speed class. This denotes the minimum sustained writing speed that the card can maintain. U1 guarantees a minimum write speed of 10MB/s, while U3 cards offer a minimum of 30MB/s. These speed classes ensure that the cards can support certain applications, with U1 suitable for Full HD video and U3 for 4K or higher resolution video.

Do SD cards degrade over time?

Yes, like all forms of digital storage, SD cards do degrade over time. This degradation occurs due to the wearing out of the flash memory cells inside the card every time data is written, erased, and rewritten. This process, called the “write/erase cycle”, gradually weakens the card’s storage ability and can lead to data loss or card failure. However, for most everyday users, an SD card will usually last for many years before this degradation becomes noticeable. It’s important to regularly back up data and replace older cards to prevent unexpected data loss.


I’m a professional photographer with 17 years of experience in a wide range of photography, and over the course of my career I’ve had the opportunity to use a variety of photographic equipment now I would like to share my knowledge with you through this website. I hope becomes the go-to destination when selecting the best gears for any project. Here you can access unbiased reviews and make an informed decision when choosing gears.

Sittha Sathutham Photographer and Writer

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