Test hard disk read and write speed under CentOS

This is on the server, read and write super fast.

Write speed

$dd If=/dev/zero bs=1k count=1000000 of=1gb.file

1000000+0 Records in
1000000+0 Records out
1024000000 bytes (1.0 GB) copied, 5.13676 seconds, 199 MB/s

Read speed

$dd if=1gb.file bs=64k |dd of=/dev/null

[Haibo@localhost ~]$ dd if=1gb.file bs=64k |dd of=/dev/null
15625+0 Records in
15625+0 Records out
1024000000 bytes (1.0 GB) copied, 6.37813 seconds, 161 MB/s
2000000+0 Records in
2000000+0 Records out
1024000000 bytes (1.0 GB) copied, 6.37891 seconds, 161 MB/s

Read and write speed

$DD if=1gb.file Of=2gb.file bs=64k

15625+0 Records in
15625+0 Records out
1024000000 bytes (1.0 GB) copied, 2.21364 seconds, 463 MB

This is on the local virtual machine.

[Root@localhost ~]# dd If=/dev/zero bs=1k count=1000000 of=1gb.file
1000000+0 Records in
1000000+0 Records out
1024000000 bytes (1.0 GB) copied, 39.6289 seconds, 25.8 MB/s
[Root@localhost ~]#
[Root@localhost ~]#
[Root@localhost ~]# dd if=1gb.file bs=64k |dd of=/dev/null
2000000+0 Records in
2000000+0 Records out
1024000000 bytes (1.0 GB) copied, 39.8982 seconds, 25.7 MB/s
15625+0 Records in
15625+0 Records out
1024000000 bytes (1.0 GB) copied, 39.9039 seconds, 25.7 MB/s
[Root@localhost ~]# dd if=1gb.file of=2gb.file bs=64k
15625+0 Records in
15625+0 Records out
1024000000 bytes (1.0 GB) copied, 46.391 seconds, 22.1 MB/s

The linux4 version is timed with time.

[xxx]$ time DD If=/dev/zero bs=1k count=1000000 of=1gb.file

1000000+0 Records in

1000000+0 Records out

Real 0m2.035s

User 0m0.114s

SYS 0m1.921s

Write Speed: 1000m/2.035=491m

[xxx]$ time DD if=1gb.file bs=64k |dd of=/dev/null

15625+0 Records in

15625+0 Records out

2000000+0 Records in

2000000+0 Records out

Real 0m2.420s

User 0m0.368s

SYS 0m1.889s

Read speed: 1000m/2.420=413m