I seriously doubt it will 70MBps. usb 2.0 is limited to just 60 MBps and that also is rarely achieved by flash drives and cards
from wikipedia:
Modern flash drives have USB 2.0 connectivity. However, they do not currently use the full 480 Mbit/s (60MB/s) which the USB 2.0 Hi-Speed specification supports because of technical limitations inherent in NAND flash. The fastest drives currently available use a dual channel controller, although they still fall considerably short of the transfer rate possible from a current generation hard disk, or the maximum high speed USB throughput. (...)
Typical fast drives claim to read at up to 30 megabytes/s (MB/s) and write at about half that speed. This is about 20 times faster than USB 1.1 "full speed" devices which are limited to a maximum speed of 12 Mbit/s (1.5 MB/s).