The dd command provides a simple way to measure sequential I/O performance. The following shows a sequential read of 1GB (1024MB). There are 1024 1MB (1024KB) reads:
root:~# time -p dd if=/dev/zero of=2delete.file bs=1024k count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 17.5714 seconds, 61.1 MB/s
real 17.91
user 0.00
sys 2.62
The megabytes per second can be calculated as follows:
root:~: echo 1024 / 17.91 | bc
57
1GB/17.91 sec = 57 MBps