# Mrconvert is very slow

**URL:** https://community.mrtrix.org/t/mrconvert-is-very-slow/6448
**Category:** Uncategorized
**Created:** [March 1, 2023, 2:26am UTC](https://community.mrtrix.org/t/mrconvert-is-very-slow/6448 "2023-03-01T02:26:21Z")
**Posts on this page:** 1
**Showing post:** 2

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### Author: ![jdtournier](https://community.mrtrix.org/user_avatar/community.mrtrix.org/jdtournier/32/2594_2.png) [@jdtournier](https://community.mrtrix.org/u/jdtournier)
#### Post date: [March 1, 2023, 1:24pm UTC](https://community.mrtrix.org/t/mrconvert-is-very-slow/6448/2 "2023-03-01T13:24:43Z")

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Hi @zzcpage,

All MRtrix commands are already multi-threaded, this should already be using all available cores – assuming this hasn’t been over-ridden by command-line arguments (via [the `-nthread` option](https://mrtrix.readthedocs.io/en/latest/reference/commands/mrconvert.html#standard-options)), the [MRTRIX\_NTHREADS](https://mrtrix.readthedocs.io/en/latest/reference/environment_variables.html#envvar-MRTRIX_NTHREADS) environment variable, or the [NumberOfThreads](https://mrtrix.readthedocs.io/en/latest/reference/config_file_options.html#cmdoption-arg-numberofthreads) config file variable. You can verify how many threads are actually being used with the `-debug` option, which should report something like this (along with a lot of other information):

```auto
mrconvert: [DEBUG] launching 32 threads "loop threads"...

```

Assuming this isn’t the issue, [this wiki article](https://community.mrtrix.org/t/linux-slow-performance-when-handling-large-images/1831) may be relevant?

All the best,  
Donald.

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