Sony is introducing its next-generation of XQD memory cards, the S Series. Aimed at sports photographers, the new cards offer sustained read and write speeds of 168MB/s, considerably swifter than the first generation XQD rate of 125MB/s. The increased speed also means that XQD is now faster than the (theoretical) maximum interface speed of the CompactFlash cards Sony hopes the new standard will replace.

The XQD format was originally developed by SanDisk, Sony and Nikon, and has the backing of the CompactFlash Association, but currently only Sony is making the cards. The first (and only) commercially available camera with an QXD slot is Nikon's D4. Sony says that pairing a new S Series card with Nikon's high-end camera enables it to capture a non-stop burst of 108 RAW frames. In keeping with the sports photographers theme, Sony boasts that "at a shooting speed of 10fps, this lets photographers document the men’s 100m sprint final from start to finish in a single, sustained burst of RAW images."

Sony's 64GB XQD S Series card will be available internationally this month, with a 32GB version available in September or October. There's no word on US or European pricing just yet, but the pair have been priced in Japan at ¥60,000 (around $754) for the 64GB card and ¥40,000 ($503) for the 32GB model.

Update: Sony has announced US pricing for both cards: $259.99 and $459.99 for the 32GB and 64GB models, respectively.