The CompactFlash Association announced a new media card format last month, and now Sony and Nikon have introduced the first media and digital cameras, respectively. But what exactly is an XQD memory card? Read on for the details.
A Different Type of Media for Different Type of Camera
Most consumers have grown used to the standard SD card for digital media. It is become ubiquitous in consumer and even semi-pro digital cameras, computers, and other devices from phones to game machines. SD (short for Secure Digital) is the descendent of the basic MultiMediaCard (MMC) format introduced in the mid-90’s. Like MMC, SD uses a simple and basic transfer mechanism rooted in the interface of flash memory chips themselves.
The SD card format has been continually updated and refined, culminating in the current SDHC and future SDXC formats used by the most advanced consumer cameras today. But SD has many limitations, and even the highest speed SD cards cannot meet the demands of fast shooting many-megapixel and pro video cameras.
Professional cameras, including full-frame digital SLR and high definition video cameras, typically use higher bandwidth formats like CompactFlash or P2. These cards may not seem all that impressive on paper, but their real-world performance justifies their extreme pricing. CompactFlash is based on now-outdated computer standards, including PCMCIA (16-bit ISA bus) and ATA, though in a smaller form factor. P2, the Panasonic format, also uses the 16-bit PCMCIA interface as well as its form factor.
XQD: A Next-Generation Memory Card Format
The new XQD card format is philosophically similar to CompactFlash in that it uses a high-speed computer bus rather than a flash interface. XQD adopts PCI Express version 2 for 2.5 Gbps throughput, with 5 Gbps promised in the future. The physical form factor falls in between CompactFlash and SD, and the CompactFlash Association suggests we will see terabyte-sized cards in the not so distant future.
XQD will likely see rapid adoption from CompactFlash adherents like Nikon and Canon. Sony appears to be getting on the XQD bandwagon as well, at least on the media side, and I expect that their future full frame cameras and pro video equipment we use the format. One expects Olympus, Fujifilm, and niche players like Sigma, Leica, and Hasselblad to join the XQD team as well. The big question is Panasonic, which seems satisfied with P2.
Although SDXC appears promising, implementation details have caused it to stumble out of the gate. The use of MBR partitioning limits capacity to “just” 2 TB, and not everyone loves the appointed exFAT filesystem. Plus, initial SDXC cards poke along even slower than conventional (and far cheaper) SDHC alternatives.
In contrast, Sony’s first batch of XQD cards are 4 times faster, allowing them to keep up with the punishing data rates generated by the new 16 megapixel Nikon D4 DSLR. With Sony set to introduce a 24 megapixel A99 and 36 megapixel hybrid mount full frame camera, it is very likely that this performance will come in handy!
Stephen’s Stance
XQD is complementary to SDXC, a high-bandwidth, high-capacity alternative for professional cameras. It is likely to be adopted by makers of professional or full frame digital SLR cameras, and one expects it to make a big splash in the digital video market as well. Future high megapixel prosumer cameras may feature both XQD and SDXC slots, giving consumers an alternative for maximum performance.
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