#!/bin/bash

if [ -z "$1" ]; then
    echo "${0##*/}: output device or file is not specify"
    exit 1
fi

for((k=1;k<17000;k*=2)); do
    echo bs=$((128*k)) count=$((1024*1024/k)):
    dd if=/dev/zero of="$1" bs=$((128*k)) count=$((1024*1024/k)) conv=sync
    echo
done