Fast Copy

How to use Robocopy multi-threaded feature to speed up file copy on Windows 10

When you have to copy a large number of files to another drive, Robocopy can significantly speed the process with its multi-threaded feature — here's how to use it.

Windows 10 Robocopy multithreaded

On Windows 10, when you need to copy files to another drive, you typically use the standard select, copy, and paste process. Although this works perfectly fine, speed becomes a bottleneck as transferring many files can take a very long time.

As an alternative, many savvy users use Robocopy (Robust File Copy), a command-line tool built into Windows 10 that offers more features to move data to a different location more quickly. One particular feature that makes Robocopy special (and often overlooked) is its multi-threaded feature that allows copying multiple files simultaneously. Instead of one file at a time using the copy feature built into File Explorer.

In this guide, you will learn to use the multi-threaded copies feature on Robocopy to speed up the transfer process of files and folders to another drive on Windows 10.

How to use multi-threaded feature with Robocopy

To use the Robocopy multi-threaded feature to copy files and folders to another drive faster, use these steps:

  1. Open Start on Windows 10.

  2. Search for Command Prompt, right-click the result, and select the Run as administrator option.

  3. Type the following command to copy the files and folders to another drive and press Enter:

    robocopy C:\source\folder\path\ D:\destination\folder\path\ /S /E /Z /ZB /R:5 /W:5 /TBD /NP /V /MT:32

    In the command, make sure to update the source and destination paths and the options. For example, this command copies data from the drive “C” to “D” and uses the “32” threads for copying:

    robocopy C:\Users\admin\Documents D:\Users\admin\Documents /S /E /Z /ZB /R:5 /W:5 /TBD /NP /V /MT:32

    Robocopy with multi-threaded option
    Robocopy with multi-threaded option

Robocopy command breakdown

Robocopy has many features, and in the command shown in this guide, we’re using the following switches to make copy reliable and fast.

  • /S — Copy subdirectories, but not empty ones.
  • /E — Copy Subdirectories, including empty ones.
  • /Z — Copy files in restartable mode.
  • /ZB — Uses restartable mode. If access is denied, use backup mode.
  • /R:5 — Retry 5 times (you can specify a different number, the default is 1 million).
  • /W:5 — Wait 5 seconds before retrying (you can specify a different number, the default is 30 seconds).
  • /TBD — Wait for share names To Be Defined (retry error 67).
  • /NP — No Progress – don’t display percentage copied.
  • /V — Produce verbose output, showing skipped files.
  • /MT:32 — Do multi-threaded copies with n threads (default is 8).

The most important switch to focus on in the above command is /MT, which is the switch that enables Robocopy to copy files in multi-threaded mode. If you do not set a number next to the /MT switch, the default number will be 8, which means that Robocopy will try to copy eight files simultaneously. However, Robocopy supports 1 to 128 threads.

In this command, we are using 32, but you can set it to a higher number. The only caveat is that using a higher number will cause higher resource usage and bandwidth. If you have an older processor, using a high number will affect performance. As a result, make sure to test before executing the command with a high number of threads.

Once you complete the steps, you will notice that copying files and folders will take significantly less time. 

You are not limited to copying files and folders to an external or internal drive, and this also works to migrate files over the network.