SD express cards with NVMe and PCIe logos
SD Association

SD cards are about to get bigger and faster. The new SD Express standard will increase the maximum capacity and speed significantly. SD Express cards are backward compatible with your current hardware, but you’ll need new hardware for maximum speeds.

SD Cards Are Reaching Their Current Limits

Since we use SD and microSD cards in 3D cameras, action cameras, ever more powerful smartphones, DSLR cameras, tablets, video game consoles, and even cars, there are ever-increasing demands for storage space, as well as faster read and write speeds.

SanDisk recently announced what it called the world’s fastest 1 TB microSD card, touting read speeds of 160 MB/s, which is enough to “transfer 1000 high-resolution photos and 30 minutes of 4K video (24GB) in less than 3 minutes.” Some cards have lower storage capacity, but higher write speeds, such as the Delkin 128 GB microSD card that boasts right speeds at 300 MB/s. But manufacturers are already pushing the limit of the current standards. The theoretical limit for SDXC, for instance, is 2 TB.

SD Cards Are Getting SSD Protocols For Faster Speeds

PCI Express and NVM express logos
SD Association

Through the incorporation of PCIe (Peripheral Component Interconnect Expres) and NVMe (Non-Volatile Memory Express) protocols, SD cards will have a new theoretical limit of 985 MB/s, more than six times as fast as the 1 TB SanDisk cards. If PCIe and NVMe sound familiar to you, that’s because they’ve been used for SSDs for a while now, and SD Express cards will be able to serve as removable solid state drives.

The SD Association says these new speeds will allow for super slow motion, 8K video and add support for raw continuous burst mode, which will be a boon to digital photographers. Additionally, by incorporating PCIe 3.1, SD Express cards can consume less power than the cards came before it. In theory, this should contribute to better battery life on mobile products, how much though is unclear.

Overall, the idea is that leveraging existing technologies will speed adoption, as new testing equipment and development processes shouldn’t be needed. Manufacturers can use what they already know from creating solid state drives.

Storage Capacities Are Increasing, Too

three microsd express cards
SD Association

As part of the transition, SD and microSD cards are seeing a size increase, pushing the upper limit from 2 TBs to 128 TBs. Cards capable of greater than 2 TBs will be marked as SDUC, adding to the SDHC and SDXC categories.

As always, read and write speeds are separate from storage capacity, so you will see SDHC and SDXC cards marked as SD Express and capable of faster write speeds. And all these benefits are coming to both SD and microSD cards, and SD Express cards are backward compatible with previous devices.

They’re Backwards Compatible, But You Lose the Speed

All of this amazing speed is due in part to a new row of pins found on SD Express (And SD UHS-ii) cards. Unfortunately, that means your current devices can’t make use of those pins, they lack the necessary hardware. But, according to the SD Association, you’ll still get the extra storage.

As the association explains it in its whitepaper, “the card and device may not reach its best performance capability, but the consumer will gain access to all content. SD Express continues this long-standing promise by keeping the ability to operate the new cards in billions of existing products available in the market through its legacy SD interface.”

When Can I Buy One and How Much Will It Cost?

There aren’t any microSD cards with the telltale “Express” branding in stores yet. The SD Association, which is the industry group that oversees this standard, announced the new microSD Express standard at Mobile World Congress 2019 on February 25, 2019. It’s part of the new SD 7.1 specification. The SD Express standard was announced back on June 26, 2018, as part of the SD 7.0 specification.

The SD Association didn’t announce any sort of launch date when microSD Express cards would be available from hardware manufacturers, nor have any SD Express cards appeared on the market since the announcement back in June. We’re not sure when they will be available, what manufacturers will make them, or how much they’ll cost. We also don’t know when devices compatible with this new standard will be available to fully take advantage of the higher speeds. All we know is the standard is out there and devices should eventually launch to take advantage of it.

Josh Hendrickson Josh Hendrickson
Josh Hendrickson has worked in IT for nearly a decade, including four years spent repairing and servicing computers for Microsoft. He’s also a smarthome enthusiast who built his own smart mirror with just a frame, some electronics, a Raspberry Pi, and open-source code.
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