Figure 2. I/O Rates for three parallel I/O approaches. Blue curves for ALL-PE Global I/O with direct access, without MPI. Sec.2.C. Magenta curves Single-PE I/O + MPI, Sec.2.A. Red curves for mix Multi-PE I/O + MPI where a fraction of PEs access the file with direct access. Sec.2.D. The single file size is 128MB. Striped over 16 disk partitions.