HDF5 benchmark looks bogus, it's not clear what exactly the author meant by it and how the data was stored/retrieved. With proper filters set up, it should beat any csv reader by both (uncompressed) throughput and runtime
It looks like they are comparing (in the chart) throughput on each of their file formats in bytes, rather than records. So, they are slower than HDF5, but eat up more resources doing so (which I think is meant to suggest they are leaving less to waste).