The Secure Digital (SD) memory card standard is reportedly slated for a major revamp next year, one that will The new standard will maintain similar external card dimensions to ensure backward compatibility. As a result, newer cards will be able to rely on parallel transfers when used on older readers, but you’ll need to update your hardware to make use of the higher speed. Keep in mind that the 300MB/s transfer rate is merely what the interface is capable of, so it remains to be seen if cards can actually push this number to the limit.