Linux Hard Drive Speed Test command

Hdparm command to test the hard disk speed.
Parameters:
-A indicates whether the disk pre-read function is disabled. For reading large files, this obviously improves the performance.
-A: Set the hard drive cache read feature. It may be hard disk cache Switch
-G: displays the disk's magnetic track, Head, magnetic area, and other parameters.
-I displays the hardware specification information of the hard disk, which is provided by the hard disk itself at startup.
-I directly reads the hardware specification information provided by the hard disk.
-P: Set the PIO mode of the hard disk. Www.jbxue.com
-Tt evaluates the Read efficiency of the hard disk and the Read efficiency of the hard disk cache.
-U <0 or 1>. Other interruption requirements can be executed simultaneously during hard disk access.
-V displays the hard disk settings.

Hdparm-tT/dev // dev/sda3: 2408 MB in 2.00 seconds = 1203.96 MB/: 352 MB in 3.01 seconds = 116.83 MB/sec