In earlier
work we proposed a three-phase I/O approach to write
data in parallel in IDX file format. The first phase involved
restructuring of simulation data into large blocks (powers of 2) while preserving the original multidimensional format.
This facilitated optimized HZ ordering followed by efficient
I/O aggregation (second phase) and ending with actual disk-
level I/O writes (third phase). By adopting this three-phase
I/O we were able to mitigate the shortcomings of small disk
accesses as well as unaligned and discontinuous memory access. Figure 1 illustrates the three phases of PIDX.