# Segmentation File Working Slowly

**URL:** <https://discourse.slicer.org/t/segmentation-file-working-slowly/6670>\
**Category:** Support\
**Tags:** segmentation\
**Created:** [May 1, 2019, 10:18pm UTC](https://discourse.slicer.org/t/segmentation-file-working-slowly/6670 "2019-05-01T22:18:04Z")\
**Posts on this page:** 1\
**Showing post:** 6

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**Author:** ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)\
**Post date:** [May 3, 2019, 12:13am UTC](https://discourse.slicer.org/t/segmentation-file-working-slowly/6670/6 "2019-05-03T00:13:07Z")

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I tried it on Windows and editing seemed to work fine. There is around 5 seconds delay with the Draw tool, but not 30-90 as you reported, and slice changes and 3D view are responsive.  
For me memory usage didn’t go above 2GB, but when I saved the segmentation to file, it went up to 10+GB and it was indeed slow.

Your image seems quite large resolution (0.211 x 0.05 x 0.05mm) but hard to tell without the master volume. Try subsampling them like this:

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/4/4/444cb656d949199440f1955c2c384c12c2ff521d.png)

Also the segment ‘Pontine Nuclei - Right’ is very fragmented, maybe it causes slowdown with  
operations like surface conversion. Smoothing won’t help this one but you can make it solid.

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