copy from emmc to sdcard:
Device:         rrqm/s   wrqm/s   r/s   w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
mmcblk1           0.00   718.80 542.80  5.50  2171.20  2673.20    17.67     6.99   11.68   1.62  88.59
mmcblk0           0.00     0.00 17.00  0.00  2176.00     0.00   256.00     0.10    6.11   6.11  10.39

copy from sdcard to emmc:
Device:         rrqm/s   wrqm/s   r/s   w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
mmcblk1         543.74     0.00 36.84  0.00  2322.32     0.00   126.09     0.15    4.05   3.74  13.76
mmcblk0           0.00    13.51  0.30  5.81     0.15  2071.32   678.49   158.37 17942.23 163.93 100.10