# time dd if=/dev/sda1 bs=64k count=10000 of=/dev/null bs=64k
10000+0 records in
10000+0 records out
655360000 bytes (655 MB) copied, 20.2197 seconds, 32.4 MB/s

real    0m20.450s
user    0m0.000s
sys     0m0.536s