ROOT I/O improvements

Abstract

In the past year, the development of ROOT I/O has focused on improving the existing code and increasing the collaboration with the experiments experts. Regular I/O workshops have been held to share and build upon the various experiences and points of view. The resulting improvements in ROOT I/O span many dimensions including reduction and more control over the memory usage, reduction in CPU usage as well as optimization of the file size and the hardware I/O utilization. Many of these enhancements came as a result of an increased collaboration with the experiments development teams and their direct contributions both in code and quarterly ROOT I/O workshops.