I'm trying to find out why my application is very slow on a certain machine (runs fine everywhere else). I think i have traced the performance-problems to hard-disk reads and writes and i think it's simply the very slow disk.

What tool could i use to measure hd read and write performance under Windows 2003 in a non-destructive way (the partitions on the drives have to remain intact)?


There is a built-in disk performance checker in Windows called winsat:

winsat disk -drive g

(Run winsat with Administrator privileges)

More info: Info on winsat disk on technet.microsoft.com/en-us/library/cc742157.aspx


C:\WINDOWS\system32>winsat disk -drive g
Windows System Assessment Tool
> Running: Feature Enumeration ''
> Run Time 00:00:00.00
> Running: Storage Assessment '-drive g -ran -read'
> Run Time 00:00:04.17
> Running: Storage Assessment '-drive g -seq -read'
> Run Time 00:00:08.64
> Running: Storage Assessment '-drive g -seq -write'
> Run Time 00:00:17.47
> Running: Storage Assessment '-drive g -flush -seq'
> Run Time 00:00:03.53
> Running: Storage Assessment '-drive g -flush -ran'
> Run Time 00:00:04.16
> Disk  Random 16.0 Read                       21.05 MB/s          6.0
> Disk  Sequential 64.0 Read                   38.29 MB/s          4.9
> Disk  Sequential 64.0 Write                  39.67 MB/s          4.9
> Average Read Time with Sequential Writes     1.324 ms          7.4
> Latency: 95th Percentile                     2.585 ms          7.3
> Latency: Maximum                             26.977 ms          7.9
> Average Read Time with Random Writes         1.299 ms          8.1
> Total Run Time 00:00:39.41
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    Finally a solution which is a) build in b) command line - Thanks a lot. To use it on a 2012 Server Core OS I had co copy the files winsat.exe, d3d11.dll, dxgi.dll, d3d10.dll, d3d10_1.dll, d3d10_1core.dll, d3d10core.dll from a windows 8 computer. – Jürgen Steinblock Jul 20 '15 at 8:14
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    You have to run the command prompt as an administrator, otherwise it pops a new command prompt and disappears as soon as it's finished, taking the results with it. – David Krider Oct 14 '15 at 11:05
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    Unfortunately doesn't work on virtual servers :( – Stalinko Jul 15 '16 at 9:44
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    @mtk It looks like the WinSAT score assigned to the result. en.m.wikipedia.org/wiki/Windows_System_Assessment_Tool – David d C e Freitas Feb 6 '17 at 20:01
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    Unfortunately does not support software RAID. – Drew Noakes Oct 11 '18 at 14:15

HD Tach has been end of lifed. HD Tune appears to be equivalent: http://www.hdtune.com/

HD Tune screenshot

  • 2
    Pretty graphs FTW! +1 – Iain Holder Jan 27 '09 at 10:51
  • The link is dead and there's now a HD Tach End of Life Announcement at their website saying it's no longer supported. – Hugo Mar 27 '12 at 12:49
  • @Hugo good spot, have updated my answer accordingly – TopBanana Mar 29 '12 at 9:00
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    the free version of HD Tune 2.55 does not allow to benchmark disk write:( – Andrej Adamenko Jul 4 '15 at 3:30

For those who might be looking for something capable of testing SQL type scenarios there's Diskspd.exe which has superseded SQLIO.


You can use Perfmon to gather physical disk based counters, such as:

  • Physical Disk (instance)\Disk Transfers/sec counter for each physical disk

  • Physical Disk(instance)\% Idle Time

  • Avg. Disk Queue Length

Or download PAL (very useful monitoring tool) and use the built-in template targeting the OS.


ATTO Disk Benchmark is freeware and does not require installation.

enter image description here


IOMeter will do this. It can do non-destructive testing by writing to its own files within the partitions.

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    Iometer sucks for the casual user. Requires an installer (wth for) tries to open friggen sockets and the UI is your typical OSS ui--ugly, way more complex than necessary, and ultimately confusing to anybody that doesn't RTFM. – user939 Aug 30 '09 at 21:41
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    Worked fine for me ;-} – ConcernedOfTunbridgeWells Aug 31 '09 at 17:59
  • The latest version 1.1.0 doesn't run in XP, version 2006.07.27 does. – ivan_pozdeev Sep 12 '16 at 15:06
  • I must admit the UI is far from being user-friendly. It still gets the job done and, unlike most other benchmarking tools, measures latency. – ivan_pozdeev Sep 12 '16 at 15:10
  • It also saves results in CSV; if you select the same file again, it appends to it - quite nice for comparison, graphing etc. – ivan_pozdeev Sep 12 '16 at 15:43

The performance counters in windows can show you transfer-speeds, current disk queue etc in order to trace the actual bottleneck on the machine when your app is running.

Look at Performance Object: Physical Disk

And look especially at the queue-counters. A disk can be very fast ad sequential reads, but as soon as it tries to access the disk simultaneously the queue might peak and give you horrible performance.


Try with Harddisk benchmark programs: http://www.hdtune.com/ http://www.passmark.com/products/pt_advdisk.htm


Besides graphical tool if you want an elaborate output to analyze the performance of your partition or hard disk, there is a nice tool called sqlio(from microsoft). The tool is CMD based, but does an awesome job when it comes to IO testing. Refer: Windows Disk Performance test

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