Dead and buried already? The latest SD card standard is fast but flawed

Vector graphic of a cartoon graveyard
(Image credit: Future,

It'd be easy to assume CFexpress is now the ultimate memory card format, with the rival SD standard left languishing in the low- to mid-range card market. But this isn't entirely true, as the SD format is quietly attempting to cling on to the high-end sector as well. It's doing this through the SD Express standard, which adopts similar PCI Express and NVMe specifications as used by CFexpress. In its fastest guise, utilising a PCIe Gen.4 x 2 lane interface, an SD Express card is theoretically capable of a 3940MB/s transfer speed. Compare this to the comparatively sluggish 312MB/s max speed of an existing UHS-II SD card and the new format performs well, on paper at least.

(Image credit: SD Association)

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Ben Andrews

Ben is the Imaging Labs manager, responsible for all the testing on Digital Camera World and across the entire photography portfolio at Future. Whether he's in the lab testing the sharpness of new lenses, the resolution of the latest image sensors, the zoom range of monster bridge cameras or even the latest camera phones, Ben is our go-to guy for technical insight. He's also the team's man-at-arms when it comes to camera bags, filters, memory cards, and all manner of camera accessories – his lab is a bit like the Batcave of photography! With years of experience trialling and testing kit, he's a human encyclopedia of benchmarks when it comes to recommending the best buys.