https://www.nas.nasa.gov/hecc/support/kb/138/ https://www.nas.nasa.gov/hecc/support/kb/performance-analysis-of-your-gpu-cuda-kernels-with-nsight-compute-cli_706.html Nsight Compute is a tool that collects metrics via hardware counters and software instrumentations for deep-dive profiling and guided performance analysis of the CUDA kernels. GPU architectures supported by Nsight Compute started with the NVIDIA... Optimizing/Troubleshooting/Code Development/Performance Analysis Mon, 14 Sep 2026 17:31:34 -0700 https://www.nas.nasa.gov/hecc/support/kb/performance-analysis-of-your-gpu-applications-with-nsight-systems_701.html NVIDIA Nsight Systems is a low-overhead statistical sampling profiler with tracing features to check overall performance of your GPU applications. The Feature Table in Get Started with Nsight Systems provides a glimpse of its capabilities,... Optimizing/Troubleshooting/Code Development/Performance Analysis Mon, 14 Sep 2026 17:24:05 -0700 https://www.nas.nasa.gov/hecc/support/kb/common-reasons-for-being-unable-to-submit-jobs_197.html Listed below are several common reasons why a job submission might not be successful. Compute Model not Recognized If you get the following message after submitting a PBS job: qsub: Unrecognized model xxx It is possible that you are... Optimizing/Troubleshooting/PBS Jobs Mon, 14 Sep 2026 16:53:28 -0700 https://www.nas.nasa.gov/hecc/support/kb/common-reasons-why-jobs-wont-start_198.html If your job does not run after it has been successfully submitted, it might be due to one of the following reasons: The queue has reached its maximum run limit Your job is waiting for resources Your mission share has run out The system is... Optimizing/Troubleshooting/PBS Jobs Tue, 01 Sep 2026 11:03:27 -0700 https://www.nas.nasa.gov/hecc/support/kb/common-login-failures-or-issues_162.html Use the information in this section to help troubleshoot any problems you encounter when logging into NAS systems. SSH Known-Hosts Error A successful host verification indicates that your Secure Shell (SSH) client has established a secure... Optimizing/Troubleshooting/Login Thu, 23 Jul 2026 10:54:04 -0700 https://www.nas.nasa.gov/hecc/support/kb/using-intel-advisor-for-better-threading-and-vectorization_566.html You can use Intel Advisor to identify issues and help you with threading and vectorization optimization on the specific Intel processors that your Fortran, C, or C++ applications run on. The software, which is available as a module on HECC systems,... Optimizing/Troubleshooting/Code Development/Performance Analysis Tue, 13 Jan 2026 16:58:56 -0800 https://www.nas.nasa.gov/hecc/support/kb/how-to-get-more-memory-for-your-pbs-job_222.html If your job terminates because the nodes it is running on do not have enough available memory, try using one or more of the methods described below. Note: The memory listed for each type of node in this article refers to the total physical memory... Optimizing/Troubleshooting/PBS Jobs Tue, 13 Jan 2026 15:27:23 -0800 https://www.nas.nasa.gov/hecc/support/kb/finding-hotspots-in-your-code-with-the-intel-vtune-command-line-interface_506.html The Intel VTune Profiler (renamed from Amplifier starting with 2020.0 version) is an analysis and tuning tool that provides predefined analysis configurations to address various performance questions. Among them, the hotspots analysis type can help... Optimizing/Troubleshooting/Code Development/Performance Analysis Wed, 31 Dec 2025 16:39:23 -0800 https://www.nas.nasa.gov/hecc/support/kb/using-hpe-mpt-environment-variables-for-pinning_286.html For MPI codes built with HPE's MPT libraries, one way to control pinning is to set certain MPT memory placement environment variables. For an introduction to pinning at NAS, see Process/Thread Pinning Overview. MPT Environment Variables Here are... Optimizing/Troubleshooting/Code Development/Process/Thread Pinning Wed, 31 Dec 2025 16:28:26 -0800 https://www.nas.nasa.gov/hecc/support/kb/using-intel-openmp-thread-affinity-for-pinning_285.html The Intel compiler's OpenMP runtime library has the ability to bind OpenMP threads to physical processing units. Depending on the system topology, application, and operating system, thread affinity can have a dramatic effect on code performance. We... Optimizing/Troubleshooting/Code Development/Process/Thread Pinning Wed, 31 Dec 2025 16:26:28 -0800 https://www.nas.nasa.gov/hecc/support/kb/processthread-pinning-overview_259.html Pinning, the binding of a process or thread to a specific core, can improve the performance of your code by increasing the percentage of local memory accesses. Once your code runs and produces correct results on a system, the next step is... Optimizing/Troubleshooting/Code Development/Process/Thread Pinning Wed, 31 Dec 2025 16:19:12 -0800 https://www.nas.nasa.gov/hecc/support/kb/using-hpe-mpt-to-run-multiple-serial-jobs_184.html You can run multiple serial jobs within a single batch job on Aitken or Electra by using the PBS scripts shown in the examples below. The maximum number of processes you can run concurrently on a single node is limited by the maximum number of... Optimizing/Troubleshooting/PBS Jobs Wed, 31 Dec 2025 14:04:24 -0800 https://www.nas.nasa.gov/hecc/support/kb/streamlining-pbs-job-file-transfers-to-lou_125.html Some users prefer to streamline the storage of files (created during a job run) to Lou, within a PBS job. Because direct access to the Lou storage nodes from the NAS compute nodes has been disabled, all file transfers to Lou within a PBS job must... Optimizing/Troubleshooting/File Transfer Wed, 31 Dec 2025 13:49:45 -0800 https://www.nas.nasa.gov/hecc/support/kb/totalview_95.html TotalView is a GUI-based debugging tool that provides control over processes and thread execution, as well as visibility into program state and variables, for C, C++ and Fortran applications. It also provides memory debugging to detect errors such... Optimizing/Troubleshooting/Code Development/Debugging Wed, 31 Dec 2025 13:39:06 -0800