New Memory Formats: CFast And XQD

Faster storage card formats are coming to the photographic world, whether you want them or not
CFast cards
First generation CFast (1.1) cards allow read/write speeds of up to 300MB per second. The CFast 2.0 specification, which is now available, offers twice the speed—up to 600MB per second. Pictured here are CFast cards from Lexar, Hoodman and SanDisk.

What do you think the oldest part of your digital camera is? It’s certainly not the sensor—those get updated all the time. It’s not the circuit board, LCD screen, battery or processor, as these are also updated with every new version. You might be right if you guessed the mirror or the optical viewfinder, but there’s another, secretly ancient component in your camera—the memory card.

While the CompactFlash (CF) card and Secure Digital (SD) cards used in cameras are ubiquitous, they’re also anachronisms. The original specifications for CompactFlash were released by SanDisk in 1994, the champion in a format war between a variety of formats that included MMC, Memory Stick, xD and more.

Even the “newer” SD card debuted before the dawn of the current millennia, shipping to the public in 1999. The collaboration between (again) SanDisk, Panasonic and Toshiba replaced the MMC format that was popular in small devices.

Having two primary card formats (instead of the dozens of related formats used before CF and SD ascended to the throne) was a huge boon as photographers could buy cards and know they’d be able to use them between devices. For a while, CF was the format for pro cameras and SD for smaller, more portable cameras.

Both the SD card and the CF card should have been replaced years ago in favor of newer technology, as has been the case with every other component in a camera, which is essentially a portable computer with a lens.

The Times Are A-Changin’

The problem is that changing standards is hard. That same format war that saw the SD card as king left a lot of cameras completely unable to be used for a lack of media. I’ve got an ancient Apple QuickTake camera I’d love to use in a retro fashion, but I’ve had a lot of trouble just getting it working with the cards and card readers from that era.

In order to get a new standard accepted, a manufacturer has to take a risk—it has to make a production run of a camera with a new format and hope it’s adopted. That’s a big cost in terms of factory setup and potentially of customer loyalty. With competing formats, no one wants to end up with the Betamax or HD-DVD equivalent in a camera.

Canon EOS-1D X Mark II uses CFast cards
The Canon EOS-1D X Mark II bridges old formats to new by including one slot for CompactFlash and one for CFast 2.0.

Difficulty of rolling out new formats aside, there are some technological advances in digital cameras that necessitate the adoption of new formats. Two new formats are now competing to become the standard in storage for professional cameras, and in the case of one of the formats, in smaller bodies as well.

Double Standards: CFast And XQD

The two standards vying for adoption are CFast and XQD, both of which are based on the current CF storage technologies but with modern components, and developed by different groups of companies.

Both XQD and CFast provide significant advantages, but they come at a time when photographers are pretty satisfied with the cards they already own. Neither format is backward-compatible, which means that sometime in the near future the piles of cards most photographers own will be relegated to being teeny-tiny coasters.

While CF and SD cards keep getting updates that make them faster and larger, there is a physical limit to their performance due to the underlying technology used to transfer data. The current high-speed SD card format called Class 10 has a top transfer rate of 14.6MB/second. The next round of XQD cards will have a top speed of 8GB/second (1000MB/second), which is around 70x faster.

That problem of dual, competing standards is a big one. It’s possible that both XQD and CFast will exist side by side, as do SD and CF now, but it’s more likely that one of the formats will become the new high-speed format and one will be dropped into the dustbin of history.

The battle lines are already being drawn: Nikon’s new D5 has an XQD version available, while the Canon EOS-1D X Mark II has both a CF and a CFast slot. Whether you want these formats or not, they’re here and they’re going to change the way you interact with your cameras.

The XQD card, which made its debut in the Nikon D4, is much more compact than the CFast alternative. The CFast card looks nearly identical to the CompactFlash card it’s based on, though it won’t fit in a CF slot, nor can it be read by a standard CompactFlash card reader.

XQD cards
Current generation XQD cards offer read/write speeds up to 500MB per second. Generation 2, when released, will double the potential maximum speed to 1000MB per second. Pictured here are XQD cards from Lexar and Sony.

Sony has stated that all of its broadcast cameras will be XQD-compatible (even though it considers the XQD card to be a “consumer” storage media), and the company has a huge installed base of devices in broadcast TV, which will help adoption.

The CFast card in the Canon EOS-1D X Mark II is also used in professional cameras from Arri and BlackMagic, so it, too, will have a good foothold in broadcast production.

There’s a spat going on between the card manufacturers, as well. While SanDisk was one of the developers of XQD, it’s not (as of press time) making XQD cards, backing CFast instead. (That’s a bit odd—developing a standard you then don’t support.)

The upshot is that consumers will once again have to make purchase decisions based on the desire of companies to have market dominance in a storage market, instead of desire to universally improve the workflow of professionals. We’re going to have to wait years to see whether XQD or CFast becomes the go-to card for the photographer, and if our investments in those different storage devices is for naught.

Video Killed The Storage Card Star

Who needs all the speed provided by these new formats, anyhow? If you’re shooting with an enthusiast-level camera or a camera that’s not cranking out massive bursts of RAW photos, CF and SD are more than capable of getting the job done. That said, if you have a need for top-end cameras like the Nikon D5 and Canon EOS-1D X Mark II, the new formats start to make sense.

If you’re shooting the EOS-1D X Mark II, for example, with a CFast 2.0 card in the available slot, the camera can capture 173 RAW files before the buffer fills. With the fastest CF card available, the same camera can only capture around 70 frames before the buffer is choking on the files. That many RAW files at a clip might seem excessive, but when you consider that the 1D X Mark II can capture images at 16fps, the difference between 11 seconds of continuous capture or 4.5 seconds is a big one.

The main motivation for faster storage cards, though, is to keep pace with video capture needs. A few years ago, camera manufacturers were all racing to see which could provide the best HD capture, and now they’re racing to add 4K video support, which pushes four times the data that HD video creates. Uncompressed (and therefore the best-quality) video requires a huge amount of bandwidth.

To think about it another way, 4K video is high enough resolution to pull an 8MP still image from the footage. This is equivalent to a camera with an 8MP sensor shooting 30 frames per second without limits (aside from the capacity of the card). That’s a staggering amount of data.

Nikon D5 and D500 use XQD cards
Nikon’s new flagship D5 is available in two versions. One model has dual CF cards slots for photographers heavily invested in the ageing standard, and another with dual XQD slots for those ready to adopt future storage formats. The D500 takes a different approach to future compatibility, with a single model that offers one SD card slot and one XQD.

The faster speeds also benefit the photographer during post-processing—I tested a Lexar XQD card and USB 3.0 XQD reader with images from the Nikon D5, and the ingest times were a fraction of what they would have been with CF or SD.

Rising Tide Lifts All Boats

Even though all photographers don’t capture video, the ones who do want the best quality video they can capture. Right now, many 4K shooters use external (read: cumbersome) devices to record the highest-fidelity image. By boosting the speed at which the cards can record data, the whole system is improved.

There are future-looking implications for this as well. The next “on the horizon” video standard is going to be 8K (though there are already people shooting in 6K in order to create a 4K video), and by the time that 8K video becomes the norm, cameras will absolutely need storage solutions like XQD and CFast.

That means that camera manufacturers need to start implementing these technologies into select cameras now so that the memory standards are widely adopted by the time the faster speeds and larger sizes of these cards are required.

Future Proof Is In The Future Pudding

Right now, XQD and CFast are implemented differently between the Nikon and Canon camps. While the previous Nikon D4 series offered dual CF and XQD cards, the company got a good amount of pushback from pro users, who often want to have matching dual slots for redundancy. With both CF and XQD, two different card types needed to be carried on any shoot. The Nikon D5 comes in either an XQD or a CompactFlash version, which probably doesn’t push adoption but does allow photographers and videographers to pick the flavor that’s right for them.

CFast and XQD card readers
Upgrading memory formats also means investing in new accessories. One that most photographers will want is a card reader, like the SanDisk Extreme PRO CFast 2.0 (left) or the Lexar Pro XQD2 USB3 (right).

Canon went the other route, putting a CompactFlash and CFast slot in the new EOS-1D X Mark II, which is getting the same pushback that Nikon received with the D4. Actually, Canon’s implementation is getting a bit more flack than did Nikon’s because the CF and CFast slots look and feel so similar. The concern is that photographers will waste valuable time trying to get the right card in the right slot.

For the near term, adoption of XQD or CFast will be purely optional. If you’re a shooter of the Nikon D5 or D500, you can use XQD or you can not. Canon shooters will be able to use CFast in the EOS-1D X Mark II, and certainly other Canon cameras are being developed right now with a CFast slot.

Soon, though, one of these type of cards will be what you reach for when you’re shooting with any camera. Those SD and CF cards on your desk will become a distant memory, and the faster speed of XQD and CFast will make the whole shooting experience better. Which card will be the champion—or if both will coexist in the same way that SD and CF do now—remains to be seen. But ready or not, a new era of storage is coming, and we’re going to have some memory card purchases to make.

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