The LHC’s Run3 will push the envelope on data-intensive workflows and, at the lowest level, this data is managed using the ROOT software framework. At the beginning of Run 1, all data was compressed with the ZLIB algorithm: ROOT has since added support for multiple new algorithms (such as LZMA and LZ4), each with unique strengths. Work is continuing as industry introduces new techniques - ROOT can benefit saving disk space or reducing the I/O and bandwidth for online and offline needs of experiments by introducing better compression algorithms. In addition to alternate algorithms, we have been exploring alternate techniques to improve parallelism and apply pre-conditioners to the serialized data.
We have performed a survey of the performance of the new compression techniques. Our survey includes various use cases of data compression of ROOT files provided by different LHC experiments. We also provide insight into solutions applied to the bottlenecks in compression algorithms for the improved ROOT performance.