# Format file and compression parameters
**URL:** https://discourse.vtk.org/t/format-file-and-compression-parameters/6784
**Category:** Support
**Tags:** file-formats
**Created:** [October 8, 2021, 8:31am UTC](https://discourse.vtk.org/t/format-file-and-compression-parameters/6784 "2021-10-08T08:31:59Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Sagues](https://discourse.vtk.org/u/Sagues)
#### Post date: [October 8, 2021, 8:31am UTC](https://discourse.vtk.org/t/format-file-and-compression-parameters/6784/1 "2021-10-08T08:31:59Z")
I’ve exported unstructured grids to xml files in ascii, binary and appended format. I’ve used LZ4 and LZMA compression with level 5 and 9.
All exported files in ascii (zlibcompression, default option) have a size of 691 Mb. If I exported in binary and appended (zlib compression) all files have a size of 216 Mb. If I used LZ4 or LZMA compression with 5 level, both formats (binary and appended) all files have a size of 180 Mb. And if I use the same compressions with 9 level all files have a size of 180 Mb too.
First of all I would like to know the diference among binary and appended, specially in relation to size files and speed of writing.
Moreover, I would like to know the diference among compressions LZ4 and LZMA.
Thank you very much
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### Author:  [@Sagues](https://discourse.vtk.org/u/Sagues)
#### Post date: [December 14, 2021, 8:44am UTC](https://discourse.vtk.org/t/format-file-and-compression-parameters/6784/2 "2021-12-14T08:44:18Z")
The following link allows to see a benchmark to know the performance of all compressors
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