SDHC vs SDXC Cards: Which Is Best for You?

If you have a DSLR and you need a new memory card where you can stock all of your pictures, your best bet are the San Disk memory cards. The problem is that there’s more than one type of memory card that you can purchase, and the options might seem confusing, especially for someone who is not an expert in the world of photography and technology. Because we want to make sure you make the best possible choice for your type of camera and your needs, we thought we’d provide you with a guide to some of the most popular types of memory cards, namely the SDHC and the SDXC. Let’s see what we can find out from a SDHC vs SDXC comparison!



First of all, we should have a look at the terminology of these two types of memory cards. SD comes from Secure Digital. Thus, SDHC means Secure Digital High Capacity, while SDXC means Secure Digital eXtended Capacity. Second of all, we should mention that there are no major differences between the two, which is what can make matters so confusing.

One of the main differences that stand out when talking about SDXC vs SDHC is the fact that the latter usually has a capacity of 4GB up to 32GB. The former can be much larger, but it’s also more expensive. So it all depends on your budget and your needs. If you don’t want to invest that much money in a memory card, then you can opt for the SDHC. If you need a lot of space on your DSLR, then you might want to purchase a SDXC.

All SD cards have a number on them, next to the logo. This number can be 2,4,6, or 10. The number refers to the class, which in turn references the transfer speed with which you can read and write images from and to your memory card. This speed is measured in megabytes per second. If you’re the kind of person who also shoots videos with their DSLR, you should know that this rating is not as important when it comes to videos. That’s because the format of the video is one of a smaller “fixed stream”, and this doesn’t take up the entire data pipe.

The way to read these class numbers is not at all complicated. The class number corresponds to the number of megabytes per second of the transfer rate. That means that a memory card inscribed with class 2 sustains a minimum transfer rate of 2 MB/s. Consequently, class 10 cards sustain a minimum of 10 MB/s.

three sdhc memory cards with different class ratings

Now that we’ve explained how to read the class rating number on a SD card, it’s time to explain what the differences between different class numbers mean for your DSLR. The Rated Speed is the maximum speed with which you can expect your memory card to read and writes files stored on it. This speed is important whenever you take a picture, because it shows you how much time you have to wait until your camera is ready to take another one. This is specifically relevant when you take still photographs, especially if they’re high-resolution. It’s also useful whenever you save pictures in RAW formats if they’re extremely large.

Consequently, if you get a faster card, you’re going to be able to take pictures faster. The speed difference is highly noticeable when it comes to taking multi-shot burst pictures on high-megapixel DSLR cameras. If you usually take a lot of still photos, and you also want to be able to transfer them to and from your memory card really fast, then you’re going to want to purchase a card that has a higher speed.

The Speed Class is what you should expect a minimum speed to be under the worst possible circumstances. This feature is more relevant when you shoot videos, because that’s the moment when your DSLR has to save a continuous stream of data. The amount of such data that the device saves is dependent a lot on the format and resolution of the video. The minimum speed we mentioned above is exactly what you need to make sure your camera records the video evenly and that there are no dropped frames to worry about.

So, even if video shooting doesn’t require a high Rated Speed, it does require a minimum Speed Class which should be compatible with your device’s specifications. No matter the kind of device you have, you’re going to find the minimum class rating required of a SDHC and SDXC.

The UHS Speed Class was first used in 2009 by the SD Association. They designed it both for SDHC and SDXC cards, so if this is an important criterion for you when choosing your memory card, you should know that both types of cards that make the topic of today’s article have it. One thing you should pay attention to is the fact that UHS memory cards only work if you have an UHS host device. If your device can’t be used as an UHS host, then it will simply use the standard Speed Class rating, not the UHS one. We advise you to purchase UHS memory cards, since they record better, have the ability to capture HD videos, and preserve a great video quality.

samsung memory card specifications
Samsung EVO memory card with the UHS feature.

Summing It All Up

We hope today’s guide to SDHC vs SDXC memory cards has proven useful in helping you decide what kind of card is better for your DSLR. Basically, there aren’t many differences between the SDHC and the SDXC cards, especially in what concerns newer technology such as the UHS Speed Class rating. The main difference between the two is the fact that the SDXC has a larger capacity than the SDHC. However, this also means that it’s pricier.

Some photographers might want their memory card to be larger, but most people can do just fine with a smaller one, such as the SDHC. In conclusion, unless you’re a professional photographer (and even if you are one, but don’t want to spend a lot of money on a memory card), a SDHC memory card is the best option for your camera.

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