Insert the SD Card in this way
Storage I/O comparison
The C2 can boot from a MicroSD card or an eMMC module. The MicroSD interface supports the higher performance UHS-1 mode as well. File access of a 512MB file (read/write) on two different storage options shows distinct performance differences. The eMMC 5.0 storage is ~7x faster than the MicroSD Class-10 card in read tests. The MicroSD UHS-1 card is ~2x faster than the MicroSD Class-10 card in read tests. The MicroSD UHS-1 card provides a great low-cost option for many applications!
To obtain the results in the storage I/O comparison graph, type the following lines at a command prompt.
Write speed command :
$ dd if=/dev/zero of=test.tmp oflag=direct bs=8M count=64
Read speed command :
$ dd if=test.tmp of=/dev/null iflag=direct bs=8M count=64