Performance measurements for hard drives and other block devices.
This program does read tests on a block device and provides several timing values for benchmark and comparison purposes. All tests are read-only; any data on the device is left untouched.
Using hdtime is quite simple. Here for example we see the timing results for
/dev/sdb, which is a 2 TB 7200 rpm mechanical hard drive:
~ # ./hdtime /dev/sdb hdtime 0.1 Copyright (C) 2012 Israel G. Lugo Reading 128.00 MiB to determine sequencial read time, please wait... Performing 200 random reads, please wait a few seconds... /dev/sdb: Physical block size: 512 bytes Device size: 1907729.09 MiB (3907029168 blocks, 2000398934016 bytes) Sequencial read speed: 92.10 MiB/s (128.00 MiB in 1.389774 s) Average time to read 1 physical block: 0.005302 ms Total time spent doing random reads: 3.035313 s estimated time spent actually reading data inside the blocks: 0.001060 s estimated time seeking: 3.034252 s Random access time: 15.171 ms Seeks/second: 65.914 Minimum time measurement error: +/- 0.000074 ms
hdtime works well with SSDs too. Here we have the timing results for a 256 GB model:
~ # ./hdtime /dev/sda hdtime 0.1 Copyright (C) 2012 Israel G. Lugo Reading 128.00 MiB to determine sequencial read time, please wait... Performing 200 random reads, please wait a few seconds... /dev/sda: Physical block size: 512 bytes Device size: 244198.34 MiB (500118192 blocks, 256060514304 bytes) Sequencial read speed: 529.72 MiB/s (128.00 MiB in 0.241636 s) Average time to read 1 physical block: 0.000922 ms Total time spent doing random reads: 0.013430 s estimated time spent actually reading data inside the blocks: 0.000184 s estimated time seeking: 0.013246 s Random access time: 0.066 ms Seeks/second: 15099.137 Minimum time measurement error: +/- 0.000028 ms