#SIZE=10240
#SIZE=2048
SIZE="$1"

COUNT=3

WRITES="0"
for i in $(seq 1 $COUNT)
do
	echo -ne "write $i:\t"
	sync
	echo 3 > /proc/sys/vm/drop_caches

	CMD="time -p sh -c \"dd if=/dev/zero of=disk.img bs=1M count=$SIZE ; sync\" 2> /dev/null"
	OUTPUT=$(sh -c "$CMD" 2>&1 | grep real | awk '{print $2}')
	echo "$OUTPUT"
	WRITES="$WRITES+$OUTPUT"
done

echo 
echo -e "average: \t$(echo "scale=2;($WRITES)/$COUNT" | bc)"
echo -e "MB/s:\t\t$(echo "scale=1;$SIZE/(($WRITES)/$COUNT)" | bc)"
echo
echo


READS="0"
for i in $(seq 1 $COUNT)
do
	echo -ne "read $i: \t"
	sync
	echo 3 > /proc/sys/vm/drop_caches

	CMD="time -p sh -c \"dd if=disk.img of=/dev/null bs=1M count=$SIZE ; sync\" 2> /dev/null"
	OUTPUT=$(sh -c "$CMD" 2>&1 | grep real | awk '{print $2}')
	echo "$OUTPUT"
	READS="$READS+$OUTPUT"
done

echo 
echo -e "average: \t$(echo "scale=2;($READS)/$COUNT" | bc)"
echo -e "MB/s:\t\t$(echo "scale=1;$SIZE/(($READS)/$COUNT)" | bc)"