This benchmark measures the speed at which large amounts of data can be written to disk using the IOFlexIO I/O method and the FlexIO file format. It does that by generating an initial data checkpoint of the simulation, saving the current contents of 100 3-dimensional grid functions of the application. These grid functions are all given the local size on each processor of 80-cubed, and use REAL*8 data types, so that each processor contributes a total of 352 MBytes to the overall initial data checkpoint.

At the moment this benchmark contains parameter files for different I/O modes, each one with a different level of parallelism when doing output: with onefile the first processor receives data from all other processors and then does all the output to disk; 8proc uses one I/O processor per group of 8 processors; eachproc writes one (chunked) checkpoint file per processor.

• BenchIO_FlexIO_onefile_80l.par
• BenchIO_FlexIO_8proc_80l.par
• BenchIO_FlexIO_eachproc_80l.par
• BenchIO_FlexIO.thornlist

These files are also contained in the benchmark's tarball.