Nikon and Sony have jumped the gun on CES by introducing a new DSLR camera (the Nikon D4) and a new series of Flash storage media (the Sony H Series). These announcements mark the beginning of the XQD Flash card era. The Compact Flash Association announced the XQD memory card format early in December. Physically, the XQD card footprint is slightly larger than an SD memory card and somewhat smaller than a Compact Flash card.
An XQD memory card is much thicker than an SD card; it’s the same thickness as a Compact Flash card.
The big change, however, is that XQD memory cards use the PCIe (PCI Express) interface rather than an existing hard disk or Flash-specific interface protocol. The current XQD interface format calls for a 2.5Gbps data rate, permitting write speeds of 125Mbytes/sec or greater. There’s a plan in place to move to 5Gbps in the future. Of course, this new Flash memory card format has some pretty big implications for SoC designers selecting an interface protocol for Flash cards.