The Professional 2933x XQD 2.0 is claimed to be the fastest XQD card on the market today.
Designed for use with the latest generation of high-definition camcorders and high-resolution DSLRs, the new XQD 2.0 cards deliver read transfer speeds up to 2933x (440MB per second) and 1400x (210MB per second) respectively. These new cards support both PCI Express Gen 2 and USB 3.0 interfaces.
Leveraging the Ultra High Speed II, UHS Speed Class 3 (U3) specification, the new SDXC card offers read transfer speeds up to 300MB per second and write speeds up to 260MB per second. The card includes an SD UHS-II reader for high-speed file transfer of photos and videos from the card to any PC or Mac system.