Intel® MPI Benchmarks User Guide and Methodology Description

# IMB-NBC Benchmarks

Intel® MPI Benchmarks provides two types of benchmarks for nonblocking collective (NBC) routines that conform to the MPI-3 standard:

- Benchmarks for measuring the overlap of communication and computation
- Benchmarks for measuring pure communication time

### Tip

When you run the `IMB-NBC` component, only the overlap benchmarks are enabled by default. To measure pure communication time, specify the particular benchmark name or use the `–include` command-line parameter to run the `_pure` flavor of the benchmarks.

The following table lists all `IMB-NBC` benchmarks:

Benchmarks Measuring Communication and Computation Overlap (Enabled by Default) | Benchmarks Measuring Pure Communication Time (Disabled by Default)
--- | ---
`Ibcast` | `Ibcast_pure`
`Iallgather` | `Iallgather_pure`
`Iallgatherv` | `Iallgatherv_pure`
`Igather` | `Igather_pure`
`Igatherv` | `Igatherv_pure`
`Iscatter` | `Iscatter_pure`
`Iscatterv` | `Iscatterv_pure`
`Ialltoall` | `Ialltoall_pure`
`Ialltoallv` | `Ialltoallv_pure`
`Ireduce` | `Ireduce_pure`
`Ireduce_scatter` | `Ireduce_scatter_pure`
`Iallreduce` | `Iallreduce_pure`
`Ibarrier` | `Ibarrier_pure`

## See Also

Measuring Communication and Computation Overlap
Measuring Pure Communication Time