recommended micro sd card ?

[jamesread90]

Using an Intergral 64GB USB 3.0:
Run began: Fri Jul 1 21:01:52 2016

Include fsync in write timing
O_DIRECT feature enabled
Auto Mode
File size set to 102400 kB
Record Size 4 kB
Record Size 16 kB
Record Size 512 kB
Record Size 1024 kB
Record Size 16384 kB
Command line used: iozone -e -I -a -s 100M -r 4k -r 16k -r 512k -r 1024k -r 16384k -i 0 -i 1 -i 2
Output is in kBytes/sec
Time Resolution = 0.000001 seconds.
Processor cache size set to 1024 kBytes.
Processor cache line size set to 32 bytes.
File stride size set to 17 * record size.
random random bkwd record stride
kB reclen write rewrite read reread read write read rewrite read fwrite frewrite fread freread
102400 4 1816 1668 5914 4980 5395 929
102400 16 5987 6767 18200 17952 17514 3320
102400 512 16531 17967 32526 33244 32805 12625
102400 1024 14803 19849 35492 36330 36312 14429
102400 16384 13931 11563 37908 37925 37153 14658

iozone test complete.