执行测试命令之前,一定先清除缓存:
# echo 3> /proc/sys/vm/drop_caches

SD卡读取的速度
# echo 3> /proc/sys/vm/drop_caches
# time dd if=/dev/mmcblk0 of=/dev/null bs=1M count=500 conv=sync
500+0 records in
500+0 records out
524288000 bytes (524 MB) copied, 0.20453 s, 2.6 GB/s

real 0m0.206s
user 0m0.000s
sys 0m0.204s


SD卡写的能力:
# echo 3> /proc/sys/vm/drop_caches
# time dd bs=1M count=500 if=/dev/zero of=/mnt/aa
500+0 records in
500+0 records out
524288000 bytes (524 MB) copied, 11.2617 s, 46.6 MB/s

real 0m11.378s
user 0m0.000s
sys 0m1.092s

 

参考文献:https://blog.csdn.net/benkaoya/article/details/70112094

 

posted on 2018-07-20 11:02  宅女士  阅读(2423)  评论(0编辑  收藏  举报