Guide to SDXC Memory Cards

These cards get the most use in digital camcorders and digital cameras

sd card breakdown


Jason Gillikin

SDXC cards are flash memory cards optimized for digital camcorders and digital cameras that offer less than 4K video quality.

SDXC vs. SDHC vs. SD Card

SDXC cards are essentially a higher-capacity version of the SDHC card, which itself is a higher-capacity version of the original SD card. SDXC cards start at capacities of 64GB and can grow to a maximum theoretical capacity of 2TB. By contrast, SDHC cards can only store up to 32GB of data and the venerable SD card can only handle up to 2GB.

For camcorder owners, SDXC cards hold out the promise of storing many more hours of high-definition video footage than what you can store on an SDHC card.

SDXC Card Speed

In addition to offering higher capacities, SDXC cards are also capable of faster data transfer speeds, with a maximum speed of 300 MB/s. In contrast, SDHC cards can achieve up to 10 MB/s. To help you find the right speed, these cards group into four classes: Class 2, Class 4, Class 6 and Class 10. Class 2 cards offer a minimum sustained data rate of 2 megabytes per second, Class 4 of 4 MB/s, Class 6 of 6 MB/s, and Class 10 of 10 MB/s. Depending on which manufacturer made the card, the speed class will either be prominently displayed or buried in the specs. Either way, you should keep an eye out for it.

For standard-definition camcorders, an SD/SDHC card with a Class 2 speed is all you need. It’s fast enough to handle the highest quality standard definition video you can record. For high-definition camcorders, cards with a Class 4 or 6-speed rating are fast enough to handle the data transfer rates of even the highest end high definition camcorders. While you may be tempted to spring for a Class 10 card, you'll be paying for performance you don't need in a digital camcorder.

In many cases, SDXC cards will be offered at faster speeds than you need for a digital camcorder. These faster speeds offered by SDXC cards are useful for digital cameras — it supports ultra-fast burst modes — but they're not necessary for digital camcorders.

SDXC Card Cost

SDXC cards began to filter onto the market in late 2010 and early 2011. As with any new memory format offering high capacities and faster speeds, early products cost more than lower capacity, slower SDHC cards. However, as more flash-memory card makers offered SDXC cards, the costs dropped rather sharply over the next two years.

SDXC Card Compatibility

An SDXC card may work in an older device that doesn't specifically support it, but you won't enjoy the larger capacities or faster speeds. Most cameras and camcorders introduced in 2011 support SDXC. Support is more limited in cameras and camcorders introduced in 2010. If a camera takes an SDXC card it will always work with SDHC and SD cards.

Do You Need an SDXC Card?

If your device supports it, buying an SDXC card makes the most sense.

What Comes After SDXC?

In the last few years, the technology underlying flash memory cards changed. A different bus (a method of interfacing the hardware) allowed for a new class of cards with a write speed of up to 30 MB/s. This type of card is optimized for 4K video.