CFexpress cards are about to get faster. A lot faster.

The Lexar Professional CFexpress Type B Card DIAMOND Series, 512GB
(Image credit: Lexar)

The CompactFlash Association (CFA) has announced the release of the next-generation CFexpress 4.0 memory card standard. The update builds on the original CFexpress 2.0 standard developed in 2016 which is now commonplace in the digital camera sector. Version 4.0 promises to double the maximum theoretical transfer speed of a Type B card from the current 2000MB/s to 4000MB/s, all while maintaining full backward compatibility with existing CFexpress cameras and devices. If you're wondering what happened to the CFexpress 3.0 standard, well, confusingly it seems to have been skipped altogether. The seemingly non-existent CFexpress 1.0 standard did in fact exist, but was badged as XQD.

The secret to version 4.0's speed increase is the use of the PCI Express Gen4 interface, which allows for twice the transfer speed of the Gen3 interface used by current (version 2.0) CFexpress cards. Interestingly the Gen4 interface isn't exactly new - it was formally announced in 2017, with retail PC components like motherboards and graphics cards adopting the standard in 2019. As with Gen3, the final speed of PCIe Gen4 depends on how many data transfer 'lanes' have been implemented for a particular hardware application. Though both generational standards can transfer over a maximum of 16 lanes, CFexpress Type B cards only use two PCIe lanes, and Type A cards just one. However, with PCIe Gen4 doubling the speed each lane is capable of, CFexpress 4.0 Type B cards will now have a maximum transfer rate of 4000MB/s, and Type A cards up to 2000MB/s.

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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.