Memory and Disk Space Requirements
The table below lists memory requirements for benchmarks run with the default settings (standard mode) and with the user-defined settings (optional mode). In this table:
- Q is the number of active processes. 
- X is the maximal size of the passing message. 
| Benchmarks | Standard Mode | Optional Mode | 
|---|---|---|
| Alltoall | Q*8 MB | Q*2X bytes | 
| Allgather, Allgatherv | (Q+1)*4 MB | (Q+1)*X bytes | 
| Exchange | 12 MB | 3X bytes | 
| All other MPI-1benchmarks | 8 MB | 2X bytes | 
| IMB-EXT | 80 MB | 2 max(X,OVERALL_VOL) bytes | 
| IMB-IO | 32 MB | 3X bytes | 
| Ialltoall, Ialltoall_pure | Q*8 MB | Q*2X bytes | 
| Iallgather, Iallgatherv, Iallgather_pure, Iallgatherv_pure | (Q+1)*4 MB | (Q+1)*X bytes | 
| All other IMB-NBC benchmarks | 8 MB | 2X bytes | 
| Compare_and_swap | 12 B | 12 B | 
| Exchange_put, Exchange_get | 16 MB | 4X bytes | 
| All other IMB-RMA benchmarks | 8 MB | 2X bytes | 
For IMB-IO benchmarks, make sure you have enough disk space available:
- 16MB in the standard mode 
- max(X,OVERALL_VOL) bytes in the optional mode 
For instructions on enabling the optional mode, see Parameters Controlling Intel(R) MPI Benchmarks.