'Bonnie++' is a disk IO benchmark utility that allows easy IO performance testing from command line without dependencies to other packages.
1. download the tar from this page
2. untar it in your device
3. run install_bonnie.sh as root
as root type following to start the standard test:
bonnie++ -u 0 > test_result
to view the result:
cat test_result
or if you don't need to store the result, just do
bonnie++ -u 0