Computational Fluid Dynamics Software: SimFlow

SimFlow is a CFD Analysis and Modeling for Windows and Linux. Easy and intuitive Computational Fluid Dynamics (CFD) Software for your everyday CFD Analysis.

SimFlow CFD Software

Hardware Recommendation for CFD

Recommendations for hardware suitable for CFD analysis, listed in order of relevance for CPU, RAM, Disk, and GPU components.

CPU

When it comes to CFD calculations, the performance of the CPU is critical to achieving results fast. In CFD simulations, substantial data transfer occurs between memory and the CPU. While the CPU is typically capable of fast computations, it often spends a significant amount of time waiting for new data. It is crucial to maintain a balance between the core count and the number of memory channels. A commonly suggested guideline is to have approximately 2-4 CPU cores per memory channel. A larger cache and the number of memory channels (and so memory bandwidth) play a significant role and may become limiting factors. For a smaller model, a higher base clock frequency provides better performance per core and scales better.

Criteria for choosing CPU for CFD

When selecting CPU, it is best to focus on parameters in this order of importance:

  1. Memory Bandwidth (memory channels)
  2. CFD calculations do not require intricate computations on the processor but involve a substantial volume of data. Hence, more critical than the processor’s individual parameters is the memory bandwidth. This ensures the swift delivery of necessary data for calculations. Memory bandwidth is directly associated with the number of memory channels which allows for data transfer in parallel.

  3. CPU cache size
  4. Cache is a type of memory that a processor uses to store frequently accessed data. A CPU with a larger cache can help speed up CFD calculations by reducing the amount of time it takes to retrieve data.

  5. Number of cores
  6. If you plan on performing simulations of large models, then having a processor with multiple cores can significantly improve the performance of your CFD calculations. However, it’s essential to align the number of cores with the maximum memory bandwidth to ensure there is no limitation to the exchange of data. Often, memory bandwidth tends to be the limiting factor, and the potential of multiple cores is not fully utilized.

    The suggested guideline is to have 2-4 cores per memory channel.
    Hyper-threading is not beneficial in CFD calculation.

  7. High clock speed
  8. A less crucial factor appears to be the processor’s frequency. The bottleneck in CFD calculations lies in the information flow, where the majority of time is consumed. Processor operations, being relatively straightforward, typically do not constitute a time-intensive aspect.

CPU – Our Recommendations

Some specific CPUs that are often recommended for CFD calculations include the Intel Core i9 and Xeon processors and the AMD Ryzen and EPYC processors.
However, the specific CPU recommendation will depend on the type of CFD simulation you are performing and your budget.

The best CPUs for running long computations are usually server-grade CPUs, like AMD EPYC or Intel Xeon.
We recommend taking a look at the AMD EPYC series:

AMD EPYC 4th Generation
12 Memory Channels and up to 460 GB/s Memory Bandwidth

In this generation, we recommend:
AMD EPYC™ 9354 (32 cores and 256 MB L3 Cache) ~ 3500$
AMD EPYC™ 9384X (32 cores and 768 MB L3 Cache) ~ 5000$

AMD EPYC 3rd Generation
8 Memory Channels and up to 204 GB/s Memory Bandwidth

In this generation, we recommend:
AMD EPYC™ 7373X or AMD EPYC™ 7473X ~4000$
AMD EPYC™ 74F3 ~3000$

The AMD EPYC 3rd generation has a worse performance but is compatible with older and more affordable components, such as AM4 motherboards and DDR4 memory.

RAM

RAM memory is used to store simulation data and software instructions that the CPU needs to perform the calculations. The amount of RAM needed for CFD calculations will depend on the size and complexity of your simulations. For most simulations, where the number of nodes is below 10M, 32GB RAM will be well enough. However, if you run multiple analyses on one PC, it may be worth increasing the memory up to 64 GB. For the larger models above 10M nodes, we recommend 2 GB of RAM per 1M nodes.

To optimize performance, it is recommended to have one RAM module per memory channel, irrespective of the total desired RAM capacity. For instance, if there are 4 memory channels and the goal is to have 64GB of RAM, it is advisable to use 4 modules of 16GB each. The RAM latency has a minor impact on the calculation speed. If the RAM memory size is not limited for an evaluated case, the RAM latency can speed up calculations by a few percent.

If the simulation demands more memory than currently available on the machine, the data will be stored on the hard drive, leading to a notable slowdown in calculations and an increase in processing time. In such instances, we suggest upgrading the RAM memory.

RAM – Our Suggestion

  • For most simulations, where the number of nodes is below 10M, 32GB RAM will be well enough.
  • For the larger models above 10M nodes, we recommend 2 GB of RAM per 1M nodes.

Storage (HDD, SSD, M2)

Select a storage drive with ample capacity, as CFD simulations generate substantial data. Consider using a Solid State Drive (SSD) for enhanced speed compared to conventional Hard Disk Drives (HDDs) in data reading and writing. Our recommendation is to employ an SSD, (especially M2) for a system and calculations, with the option to include an HDD for data storage and backup purposes.

Storage – Our Suggestion

  • SSD/M2 (as a main drive) + HDD to store data
  • Example: SSD 2TB M.2 PCIe Gen4 NVMe + HDD 8TB

GPU

SimFlow CFD calculations do not depend on GPU processing. Hence, any NVIDIA card with 4GB or more memory, chosen based on your budget, should be suitable for post-processing tasks. There’s no need to invest in a costly Quadro card, as it is specifically tailored for CAD applications.

GPU – Our Suggestion

  • GPU card with 4GB or more memory
CFD Software

Free Download | SimFlow CFD - OpenFOAM GUI

Download