Memory Card Buyer's Guide
SD Card Types and Speeds
This guide helps you choose the right memory card for your camera, action cam, drone, or other devices. We'll cover SDXC, microSDXC, and CFexpress cards, explaining their speeds and compatibility.
Understanding SD Cards
Most cameras use Secure Digital (SD) cards. SD cards come in different capacities: SD (up to 2GB), SDHC (up to 32GB), and SDXC (up to 2TB). Newer SDUC cards offer up to 128TB but are less common. Check your camera's manual for compatibility. SDXC cards use the exFAT file system, while older SDHC cards use FAT32. Cameras format cards automatically, so you don't need to worry about this.
Speed Classes
SD cards also have speed classes indicating minimum write speeds. Class 10 or UHS (Ultra High Speed) cards are faster. UHS-I offers speeds up to 104MBps, while UHS-II (SD4.0) reaches up to 312MBps. Video Speed Classes (V60, V90) indicate minimum write speeds for video recording. V30 is suitable for 4K video, while V60 or V90 is recommended for 8K. See The Ultimate Guide to iPhone 15 Cases for more information on storage speeds.
CFexpress Cards
CFexpress cards are designed for professional cameras and offer even higher speeds. They come in two generations: CFexpress 2.0 and the faster CFexpress 4.0. You'll need a compatible reader, like those mentioned in Best USB-C Cables for Apple Devices, to take full advantage of their speed. To learn more about optimizing storage for professional use, see Best Mac Cleaner Apps for a Speedy Mac in 2025.
Choosing the Right Card
Consider your camera's capabilities and your needs when choosing a memory card. Faster cards are better for high-resolution video and burst photography. Also, check the warranty and any included software. Some brands offer lifetime warranties or data recovery services.