1. [root@zjx86r01n01 tmp]# time dd if=/dev/zero of=/tmp/testfile.dat bs=8k count=1024
    2. 1024+0 records in
    3. 1024+0 records out
    4. 8388608 bytes (8.4 MB) copied, 0.0415268 s, 202 MB/s
    6. real    0m0.079s
    7. user    0m0.000s
    8. sys    0m0.019s
    9. [root@zjx86r01n01 tmp]# time dd if=/tmp/testfile.dat of=/dev/null bs=8k 
    10. 1024+0 records in
    11. 1024+0 records out
    12. 8388608 bytes (8.4 MB) copied, 0.00453069 s, 1.9 GB/s
    14. real    0m0.008s
    15. user    0m0.002s
    16. sys    0m0.004s
    17. [root@zjx86r01n01 tmp]#