Yes, unfortunately. They just don't support it. However, it can be compressed post-mortem using a command line tool. 

Axel Hübl <notifications@github.com> schrieb:

>In src/picongpu/include/plugins/output/HDF5Writer.hpp:
>
>> @@ -257,8 +259,7 @@ class HDF5Writer : public ISimulationIO, public IPluginModule > desc.add_options() > ("hdf5.period", po::value<uint32_t > (&notifyFrequency)->default_value(0), "enable HDF5 IO [for each n-th step]") > ("hdf5.file", po::value<std::string > (&filename)->default_value(filename), "HDF5 output file") > - ("hdf5.compression", po::value<bool > (&compression)->zero_tokens(), "enable HDF5 compression") > - ("hdf5.continue", po::value<bool > (&continueFile)->zero_tokens(), "continue existing HDF5 file instead of creating a new one"); > + ("hdf5.compression", po::value<bool > (&compression)->zero_tokens(), "enable HDF5 compression"); 
>
>Say whaaaat? ￼
>Compression saves us a factor of 3 to 10 in our regular cases o.0
>
>—
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>