Photographers are in a never-ending search for improvements in performance—a bigger sensor, faster shutter speed, lighter gear, better optics. Thanks to the breakneck pace of computing (and digital cameras are really sophisticated little computers with lenses attached), we’re used to looking for regular performance boosts in our technology arsenal. After a sluggish start, where SD cards and the ancient CompactFlash have ruled the day, we’re in the midst of a revolution in memory card formats, albeit one that oddly only a few photographers seem in a hurry to embrace.
The CompactFlash card has a history that’s as long as the digital camera. Among the first cameras to use a CompactFlash slot was Kodak’s DC25, which in 1996 was just a few years after the adoption of the standard. The original Nikon D1, the first widely adopted professional digital camera, also shipped with a CompactFlash card slot, cementing its use as a professional image storage device. It wasn’t until 1999 that SanDisk’s SD card arrived, a modification of the existing, but not very popular MMC format, and pro cameras wouldn’t see the SD slot for some time.
While the CompactFlash and SD cards we’ve grown accustomed to have increased in both speed and capacity, their days are numbered. Based on older architectures, there’s a limit to what they can provide the photographer, and more importantly, videographer (since video has a higher baseline performance).
In 2012, a collaboration between SanDisk, Sony and Nikon developed the XQD card, with a write speed that could keep up with the fastest video throughput and theoretical storage sizes in excess of 2 TB. At the same time, the CompactFlash Association began work on a new CFast standard to replace CompactFlash. That resulted in two different—and incompatible—cards joining the existing market of CompactFlash and SD cards.
In 2012, Nikon also introduced the XQD slot in their D4 camera, placing it alongside the CompactFlash slot. Once that shoe dropped, we waited for cameras to include the CFast slot—and waited, and waited.
This year’s introduction of Canon’s new flagship, the EOS-1D X Mark II, ended the waiting game. It’s the first camera that’s not video-specific to use CFast 2.0, and with its arrival, we can finally talk about the budding rivalry—and choice—between these next-generation memory card formats.
Mind you, “choice” is a relative term. The Nikon D5 offers two versions, one with dual CompactFlash slots and one with dual XQD slots. The Canon EOS-1D X Mark II has a standard CompactFlash slot and a CFast slot—it’s not like you can order a pro camera with whatever you’d like inside.
Both CFast 2.0 and XQD offer enticing performance boosts over existing CompactFlash and SD card technologies, and likely will sway pros toward wanting to upgrade gear just to be able to get the benefits of faster and larger storage. It’s unlikely, however, that a photographer would move from Nikon to Canon or Canon to Nikon based solely on storage media. However, if you’re getting started or considering a platform switch, understanding the differences between the two formats is extremely useful.
Why Two New Formats?
With camera frame rates and sensor size increasing all the time, and camera processing speeds improving, manufacturers realized there was a need for a new faster memory card format that pushed beyond what the current specifications allowed. You know the feeling: Your finger is on the shutter button, then all of a sudden, the burst slows to a trickle as the buffer fills—and you miss the split-second moment you were trying to capture.
Lexar’s product marketing manager Steffi Ho, explains, “CompactFlash just wasn’t going to continue to keep up with everything coming out today, so the CompactFlash Association created this new specification called CFast. The CFast theoretical limit is over three times more than CompactFlash, at up to 600 MBps.”
CFast 2.0 uses the Serial ATA III bus, a term that may sound familiar to computer geeks because it’s the same terminology that’s long been associated with PC hard drives. The first generation of CFast was never adopted in the consumer market. The (faster, better) CFast 2.0 spec wasn’t ready until late 2012. And as often happens when technology marches on, when one technology is late to the party, another jumps into the void.
Ironically, the competing technology, XQD, was also approved and licensed by the CompactFlash Association, but it passed the finish line in December 2011, which meant it was ready in time to be incorporated into cameras in 2012. While the XQD format began as a consortium between Sony, Nikon and SanDisk, SanDisk eventually bowed out later and threw its weight behind CFast 2.0. But Nikon moved ahead and incorporated XQD into its Nikon D4, and later the D4S and D5.
Steve Heiner, Nikon’s senior technical manager, recalls, “It became Sony creating and making the XQD cards and card readers for their system, with the full awareness that we were the only 35mm camera system using it. Cards were hard to find and a little expensive, as with any new format.”
Nikon has admittedly eased into the new format. Until this year, XQD was reserved solely for the flagship cameras, the D4 and D4S. But, in 2016, that began to change with the introduction of the new D5, and the prosumer/professional cross-over model, the D500.
Heiner says we can expect to see more models adopt XQD, where it makes sense. “I think it’s a safe bet that this is a very resilient card format that’s growing. We like to give [something new] a little bit of time and then we incorporate it [in our product line]. These two cameras have been on the drawing board for years,” he says of the D5 and D500. “I was looking at plans for the D5 two-and-half years ago.”
That hefty design lead time, in part, explains why it takes so long for new card formats to get into cameras. But the format will also need to make sense for the camera’s capabilities and sensibilities, and what its target audience will shoot with that camera.
“I think there will always be a practical break,” notes Heiner of the differences between XQD and SD. “SD is a smaller format, and it enables a good, small, compact camera. If we had to put a slot in there for XQD, that would increase the size of the camera. And certain cameras weren’t designed to take advantage of the XQD card and what it can do.
“The primary reason XQD is a benefit to the photographer is, we’re talking about very heavy 14-bit raw files for high-end flagship or enthusiast cameras. The faster the frame rate gets, the more robust and thicker the file gets, and the more useful XQD memory gets,” explains Heiner. “That’s where somebody gets hit, if you’re shooting a sequence that goes beyond the number of frames [the camera and the memory card can handle]. You could go to 200 pictures without stopping. XQD could write those images so fast that you didn’t see an impact on the buffer until it was empty.”
Sports photographers and video shooters are the obvious beneficiaries of such speed, but, in fact, photographers of most stripes will benefit from the ability to capture moments without worrying about the buffer filling at an inopportune time. That’s the kind of performance that both CFast 2.0 and XQD can achieve in their current iterations on cameras like the Nikon D5 and the Canon EOS-1D X Mark II. It may make the difference between capturing every fractional rotation of a gymnast’s vault or just capturing a portion of it, for example, or capturing a dramatic moment at a wedding.
However, the performance benefit of these new formats doesn’t just lie with your raw shooting speed. With XQD and CFast 2.0, you can speed up transfer times dramatically, shaving about half, or more, off the time you’re sitting at your computer to offload images. That alone can save you time that translates into faster turnarounds for clients, or more sleep at the end of a long shooting day.
XQD and CFast 2.0 take different pathways to achieve faster performance. Each offers a vast improvement over the venerable, original CompactFlash format’s spec, which tops out at a 167 MB/s read speed and a 155 MB/s write speed. For comparison sake, the original CompactFlash cards measure 36.4mm long, 42.8mm wide and 3.3mm thick.
CFast 2.0 uses a SATA III interface inside its similarly sized, but slightly thicker (3.6mm) card enclosure. The CFast 2.0 spec has write speeds of up to 600 MB/s (Lexar’s CFast 2.0 3500x cards get up to 540 MB/s for read and 445 MB/s for write).
The form factor similarities are likely to be confusing until cameras have completely moved away from CompactFlash. As we saw during a demo of the new Canon EOS-1D X Mark II, the similar sizes are bound to lead to some confusion about which slot to put which card into, given that at first glance the cards and their respective slots appear so similar.
The XQD format uses PCI Express 3.0, or PCIe, an even newer and more compact data interface. The format can theoretically go up to 1 GB/s (i.e., 1000 MB/s) read speeds, though the current generation of cards maxes out at 500 MB/s. The cards are elongated, providing a different shape than CFast 2.0—38.5mm long, 29.6mm wide and 3.8mm thick. XQD is backward-compatible with the slower 1.0 generation, a boon if you’ve started using the format and already have invested in cards.
For now, these new formats remain the purview of higher-end digital cameras and video cameras. CFast 2.0 is in pro video cameras such as those from ARRI and Blackmagic, and in the Canon EOS-1D X Mark II. Meanwhile, XQD can be found in the Nikon D5, D500, D4S and D4, and in the Sony PXW-FS7 professional video camera.
Price and Capacity
Of the two superfast formats, CFast 2.0 has the capacity advantage, with cards up to 256 GB available today. When it comes to price, though, both CFast 2.0 and XQD continue to carry a premium over more conventional cards. A quick check of Lexar cards shows that those 3400x cards don’t come cheap: A 256 GB CFast 2.0 card sells for $675, while a 128 GB card sells for $365 and a 64 GB card sells for $200. By contrast, a 1066x 256 GB CompactFlash card sells for $300, the 128 GB sells for $145, and the 64 GB card sells for $90.
XQD’s capacity tops out at 128 GB, as of this writing, but larger cards are rumored to be coming soon. Lexar’s 2933x 128 GB XQD sells for $350, the 64 GB sells for $320, and the 128 GB sells for $350. Lexar’s slower 1400x card, which is about 40 MB/s faster than the 1066x CompactFlash cards, costs $90 for 64 GB.
The main barriers to entry for the two new formats are price, necessity and legacy investment, and those are substantial hurdles for some. Many photographers have stacks upon stacks of memory cards in their camera bags. Looking across my table, there’s a stack of a dozen high-capacity CF cards and a (smaller) stack of high-end SD cards, and many photographers have likely spent thousands of dollars on their storage solutions. For many, there’s also little compelling reason to switch now. Photographers working primarily in commercial shoots or portraits would see little up-front benefit from a faster card, although the transfer times would still be shorter.
The cards are also more expensive than their older predecessors, making it a hard investment to swallow for someone who’s not shooting video or pushing the frame rate of their camera.
Make no mistake, the storage card landscape is changing. CompactFlash cards have existed for more than 20 years, an eternity in computing technology. Cameras are increasing in speed and in resolving power at the same time, which means that new standards will become increasingly necessary. At some point, the professional photographer is going to need to abandon CompactFlash and SD; the question is only a matter of when.
Whichever way you go, your memory card “can be the weak point in your camera’s performance,” notes Nikon’s Heiner.
Choose your cards wisely, and you’ll find yourself capturing a lot more than you imagined was possible.