Strategy: Running the Engine with Parallel Processing
By default, Creo Simulate automatically selects the number of CPU's it will use during a run. For systems with one CPU, Creo Simulate always uses standard serial processing. For parallel processor machines, Creo Simulate attempts to use all CPUs on the machine. In certain situations, however, you may want to limit the number of CPUs the software can use. When making this decision, you need to balance the benefits of parallel processing against its limitations.
The main advantage of parallel processing is that it can improve solution times. Parallel processing is most likely to improve a design study run time under the following conditions:
• Only a single user is using the computer at the time of the run.
• The computer is equipped with a fast disk, ample memory, and individual processors that are fast in and of themselves.
• The ratio of elapsed time to CPU time is close to a value of 1 with one CPU.
• Your model is large, solid, and blocky in shape.
Even if these conditions are present, your elapsed run time might improve only slightly when you run the engine in parallel processing mode because parallel processing accelerates just a few phases of the overall solution process.
The main disadvantage of parallel processing is that, if you are running other jobs at the same time as Creo Simulate, you can experience performance bottlenecks. Thus, unless you expect substantial gains from using all CPUs in your system for the engine or you have no other jobs planned for your system during the engine run, you may want to limit the number of CPUs dedicated to the engine.
If you do not want to use all of the CPUs in your system for the engine job, use the configuration option sim_run_num_threads to control the number of CPUs. You can specify one of the following values:
• all—Use all of the CPUs in the system.
• all_but_1—Use all the CPUs in the system except for 1. For example, if the system has 3 CPUs, then Creo Simulate selects any 2 CPUs for the engine job.
• all_but_2—Use all the CPUs in the system except for 2. For example, if the system has 3 CPUs, then Creo Simulate selects any 1 CPU for the engine job.
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 When the system has only 2 CPUs, Creo Simulate selects both the CPUs for the engine job. |
• 2—Use any 2 CPUs in the system.
• 1—Use any 1 CPU in the system.
• half—Use half of the total number of CPUs in the system.
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When the system has odd number of CPUs, Creo Simulate selects the next lowest number of CPUs. For example, when the system has 3 CPUs, Creo Simulate selects only one CPU for the engine job.
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