savecube very slow for small chunksizes

[felixcremer]

When I save a cube with small chunk sizes the buffer size is not corrected in get_copy_buffer_size which leads to a very slow saving of the data cube. We might want to increase the buffer size in line 67 of Cubes/Rechunker.jl

[Balinus]

Hello, what would be an example of a "small chunksizes"? Is it an absolute size or is it relative to the size of the Dataset/Cube?

I'm wondering if my writing speed is due to the small chunksizes or the compression. Thanks!