How to measure random/sequential read/write on Linux. SSD considerations

Question

I wish to purchase an SSD drive for my Linux Fedora 16 work station. It will be mainly used for web development over Gnome3, IDE and a virtual server (for the web env).

I have two candidates.

• crucial m4 128gb ( have much better 4k random read )
• SanDisk extreme 3 120GB ( much faster in sequential and writes )

I wonder what will benefit my system most and if there is a tool to measure the actual random/sequential read/write on my system.

Thanks

Answer 1

实际的系统RAM更快，更便宜;）然后选择最快的系统和程序加载驱动器IIRC，即4k速度。

Answer 2

yout can try the commercial version tool named PassMark BurnInTest™ . The neweset version is BurnInTest 7.1.

also you can try the Freeware AS SSD Benchmark 1.7.4739.38088
Both BurnInTest (also available for Linux) ) and AS SSD Benchmark is for Windows Platform.
There is some utility under linux: Several I/O benchmark options exist under Linux.

1. Using hddparm with the -Tt switch, one can time sequential reads. This method is independent of partition alignment!
2. There is a graphical benchmark called gnome-disks contained in the gnome-disk-utility package that will give min/max/ave reads along with ave access time and a nice graphical display. This method is independent of partition alignment!
3. The dd utility can be used to measure both reads and writes. This method is dependent on partition alignment! In other words, if you failed to properly align your partitions, this fact will be seen here since you're writing and reading to a mounted filesystem.
4. Bonnie++

And if your want do more control of the benchmark, I recommand you to use SMARTCTL

Answer 3

You can try my benchmark described in the following that also has link to download the program:

http://www.roylongbottom.org.uk/linux_disk_usb_lan_benchmarks.htm

Latest version includes random writing. Example results are below. A run time parameter can select larger files.

 ###############################################################

 Selected File Path: 
 /media/PAT//
 Total MB    7620, Free MB    7620, Used MB       0

 Linux Storage Speed Test 64-Bit Version 1.2, Tue Dec 10 16:08:20 2013

                Copyright (C) Roy Longbottom 2012

     8 MB File         1          2          3          4          5
 Writing MB/sec       5.18      11.97      12.12      12.04      11.96
 Reading MB/sec      30.88      31.57      31.60      31.45      29.22

    16 MB File         1          2          3          4          5
 Writing MB/sec      11.90      11.95      12.26      12.07      12.14
 Reading MB/sec      30.94      31.47      31.51      31.51      30.31

    32 MB File         1          2          3          4          5
 Writing MB/sec      11.97      12.07      12.11      12.15      12.18
 Reading MB/sec      31.26      31.49      31.52      31.50      30.90

 ---------------------------------------------------------------------
 8 MB Cached File      1          2          3          4          5
 Writing MB/sec     396.50      77.49      11.19      11.01      13.36
 Reading MB/sec    2810.03    2675.62    2972.66    3139.78    3079.33

 ---------------------------------------------------------------------
 Bus Speed Block KB     64        128        256        512       1024
 Reading MB/sec      28.34      28.31      30.25      31.00      31.41

 ---------------------------------------------------------------------
 1 KB Blocks File MB >    2      4      8     16     32     64    128
 Random Read  msecs    0.52   0.51   0.50   0.50   0.50   0.50   0.52
 Random Write msecs    5.47   5.56   3.31   8.48   3.35   3.35 194.27

 ---------------------------------------------------------------------
 500 Files   Write             Read             Delete
 File KB     MB/sec  ms/File   MB/sec  ms/File  Seconds
       2       0.09    22.35     3.07     0.67    0.014
       4       0.15    26.79     6.12     0.67    0.014
       8       0.35    23.43     9.94     0.82    0.014
      16       0.74    22.12    16.16     1.01    0.014
      32       1.59    20.61    22.12     1.48    0.015
      64       3.03    21.66    28.06     2.34    0.015