Memory cards, ranked by cost per terabyte

Memory cards put removable flash storage into cameras, drones, handheld consoles, dash cams and phones. The family spans tiny microSD cards in phones and the Nintendo Switch, full-size SD cards in most cameras, rugged CompactFlash in older professional bodies, and the newest high-bandwidth CFexpress and CFast cards that feed 8K video and rapid-fire bursts. They cost far more per terabyte than hard drives or even SSDs — you’re paying for miniaturisation, ruggedness and the speed ratings that prevent dropped frames — so cards are about capability in a slot, not bulk capacity value.

The number that trips people up is speed, not size. A card’s capacity is easy, but recording high-bitrate video or shooting continuous bursts demands a guaranteed minimum write speed, expressed through a confusing stack of ratings: Speed Class, UHS Speed Class (U1/U3), Video Speed Class (V30/V60/V90) and the bus markings (UHS-I, UHS-II). Buying a card whose sustained write speed is too low causes cameras to stutter or stop recording, regardless of how many gigabytes it holds. When comparing value, first match the card type and minimum speed your device requires, then optimise $/TB within that — and buy from reputable brands, as the memory-card market is plagued by counterfeits.

Card types and the speed-class maze

Capacity is the easy part; sustained write speed is what actually determines whether a card keeps up with your camera. Match the device’s required type and speed class first, then chase value.

Video Speed Class is the rating to trust for recording: V30 (30 MB/s) covers most 4K, V60 and V90 for high-bitrate and 8K. The headline ‘read’ speed on the label is not the same as the sustained write speed your camera needs. Photographers offloading cards in the field should also see our storage for creators guide.