From this tutorial, we will check how to measure the input/output performance of a HDD, SSD, USB Flash Drive etc with the file system.
To test the read/write speed of a disk from the Linux command line using dd command.
We also need to install and use hdparm utility for measuring the read speed of a disk on Linux Mint, Ubuntu, Debian, CentOS, RHEL.
To get the accurate read/write speed, you should repeat the below tests several times (usually 3-5) and take the average result.
TEST Disk WRITE Speed using dd command:
Run the following command to test the WRITE speed of a disk:
$ sync; dd if=/dev/zero of=tempfile bs=1M count=1024; sync 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 3.28696 s, 327 MB/s
TEST Disk READ Speed using dd command:
The file tempfile, that has just been created by the previous command, was cached in a buffer and its read speed is much higher then the real read speed directly from the disk.
To get the real speed, we have to clear cache.
Run the following command to find out the READ speed from buffer:
$ dd if=tempfile of=/dev/null bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 0.159273 s, 6.7 GB/s
Clear the cache and accurately measure the real READ speed directly from the disk:
$ sudo /sbin/sysctl -w vm.drop_caches=3 vm.drop_caches = 3 $ dd if=tempfile of=/dev/null bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 2.27431 s, 472 MB/s
TEST Read/Write Speed of an External Drive using dd command:
To check the performance of some External HDD, SSD, USB Flash Drive or any other removable device or remote file-system, simply access the mount point and repeat the above commands.
Or you can replace tempfile with the path to your mount point e.g.:
$ sync; dd if=/dev/zero of=/media/user/MyUSB/tempfile bs=1M count=1024; sync
Test HDD, SSD, USB Flash Drive’s Performance using hdparm command:
hdparm is a Linux command line utility that allows to set and view hardware parameters of hard disk drives.
hdparm is available from standard repositories on the most Linux distributions. Install hdparm depending on your Linux distribution.
On Linux Mint, Ubuntu, Debian:
$ sudo apt-get install hdparm
On CentOS, RHEL:
$ sudo yum install hdparm
Run hdparm as follows, to measure the READ speed of a storage drive device /dev/sda:
$ sudo hdparm -Tt /dev/sda /dev/sda: Timing cached reads: 16924 MB in 2.00 seconds = 8469.95 MB/sec Timing buffered disk reads: 1386 MB in 3.00 seconds = 461.50 MB/sec