Microsoft DiskSpd Storage Performance Tool

DiskSpd is a free open source performance benchmarking tool by Microsoft for systems running Windows.

The program has been designed for professional use to analyze and diagnose storage performance issues without having to run a full end-to-end workload.

At its core, it can be used to test files, partitions or physical disks on devices running supported client or server versions of the Windows operating system.

DiskSpd is a command line tool which you need to run from an elevated command prompt. You can open one with a tap on the Windows-key, typing cmd.exe, holding down Shift and Ctrl, and tapping on the enter key in the end.

DiskSpd review

DiskSpd is a highly customizable I/O load generator tool that can be used to run storage performance tests against files, partitions, or physical disks. DiskSpd can generate a wide variety of disk request patterns for use in analyzing and diagnosing storage performance issues, without running a full end-to-end workload. You can simulate SQL Server I/O activity or more complex, changing access patterns, returning detailed XML output for use in automated results analysis.

The program may look intimidating at first as it ships with dozens of switches that you can add to the main command to configure specific test scenarios.

At its core though however, it is simple to execute. Use the command diskspd.exe c: to run a 10 second test on drive c of the computer using default parameters.

You can redirect the output to a text file using the > pathtotext option, e.g. diskspd.exe c: > c:\users\martin\output.txt

DiskSpd displays information about cpu usage during the test, as well as total, read and write IO.

The command diskspd.exe -c1G -b4K -t2 -d60 -a0,1 testfile1.dat testfile2.dat on the other hand creates two 1GB testfiles, sets the block size to 4KB, creates 2 threads per file, sets the cpu affinity to CPUs 0 and 1, and runs the test for 60 seconds.

You find other advanced test configuration parameters in the help file that is included with the program.

Among them options to measure the latency, start parallel sequentional I/O operations, configure write buffers, disable or configure caching, or add event tracing parameters that trace page faults, threads or Registry calls among other things.

The documentation that ships with the program is 28 pages long. It explains every test parameter in detail, provides a set of example tests and explanations, and visualizations for certain key concepts such as threading.

Closing Words

DiskSpd is a professional benchmarking tool for Windows that provides system and network administrators with the means to test drive performance thoroughly.

Home users may use it as well, but the command line nature of the program may keep the majority of users from giving it a try considering that there are several GUI applications out there .. CrystalDiskMark or ATTO Disk Benchmark for example -- that are a tad easier to use and more appealing to the eye.