Nsight Systems

Contents

Nsight Systems#

Nsight Systems is a system-wide performance analysis tool designed to visualize an application’s algorithms and identify the largest opportunities to optimize. It supports Pascal (SM 60) and newer GPUs.

A common use-case for Nsight Systems is to generate application timelines via the command line, which can later be visualised on a local computer using the GUI component. The GUI is not available on Bede.

On Bede, Nsight Systems is provided by a number of modules, with differing versions of nsys. You should use a versions of nsys that is at least as new as the CUDA toolkit used to compile your application (if appropriate).

module load nsight-systems/2023.1.1
module load nsight-systems/2022.1.1
module load nsight-systems/2020.3.1

module load cuda/12.4.1 # provides nsys 2023.4.4
module load cuda/12.0.1 # provides nsys 2022.4.2
module load cuda/11.5.1 # provides nsys 2021.3.3
module load cuda/11.4.1 # provides nsys 2021.2.4
module load cuda/11.3.1 # provides nsys 2021.1.3
module load cuda/11.2.2 # provides nsys 2020.4.3

module load nvhpc/23.1  # provides nsys 2022.5.1
module load nvhpc/22.1  # provides nsys 2021.5.1
module load nvhpc/21.5  # provides nsys 2021.2.1

To generate an application timeline with Nsight Systems CLI (nsys):

nsys profile -o timeline ./myapplication <arguments>

Nsight systems can trace mulitple APIs, such as CUDA and OpenACC. The --trace argument to specify which APIs should be traced. See the nsys profiling command switch options for further information.

nsys profile -o timeline --trace cuda,nvtx,osrt,openacc ./myapplication <arguments>

Note

On Power9 systems such as Bede the --trace option osrt can lead to SIGILL errors with some versions of nsys. As this is part of the default set default, consider passing --trace cuda,nvtx instead.

Once this file has been downloaded to your local machine, it can be opened in nsys-ui/nsight-sys via File > Open > timeline.qdrep

More Information#

Contents