HPC FAQ: Difference between revisions

If running on the same CPU hardware, a well-constructed Classic model on a good timestep is nearly always faster than HPC running on a single CPU thread (i.e. not using GPU hardware). Running a single HPC simulation across multiple CPU threads may produce a faster simulation than Classic. HPC is best run using GPU hardware. HPC run using good GPU hardware should be faster than Classic on CPU. The <u>[[Hardware_Benchmarking | Computer Hardware Benchmark]]</u> page included guidance on the fastest available hardware for TUFLOW modelling.

 

Trying to run multiple HPC simulations across the same CPU threads. If, for example, you have 4 CPU threads on your computer and you run two simulations that both request 4 threads, then effectively you are overloading the CPU hardware by requesting 8 threads in total. This will slow down the simulations by more than a factor of 2. The most efficient approach in this case is to run both simulations using 2 threads each, noting that if you are performing other CPU intensive tasks, this also needs to be considered.<br>

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Note: If Windows hyperthreading is active there typically will be two threads for each physical core. For computationally intensive processes such as TUFLOW, it is recommended that hyperthreading is deactivated so there is one thread for each core.

 

If running a simulation using a low end or old GPU device, simulations may only be marginally faster, than running Classic or HPC on CPU hardware. If running on a GPU device, high end NVidia graphics are strongly recommended. The performance of different NVidia cards varies by orders of magnitude.The <u>[[Hardware_Benchmarking | Computer Hardware Benchmark]]</u> page included guidance on the fastest available hardware for TUFLOW modelling.

 

See <u>[[HPC_Adaptive_Timestepping | HPC Adaptive Timestepping]]</u>