ZF5 official website specifications support to 64GB SD card
SanDisk 128GB [30MB / s] microSDXC mobile ultra UHS-1 C10 memory card plugged ZF 5.
Successfully read - with A1 SD Benchmark test read 21.85MB / s write 13.59MB / S
Source: http://www.mobile01.com/topicdetail.php?f=588&t=3944938&r=2&last=50577124
