Computer suitable for Lumerical simulation

xyjxyj1992xyjxyj1992 Member Posts: 4

Hello, we are trying to get a more powerful PC for running lumerical simulation. Does anyone have the recommendation for CPUs or RAMs which can help accelerate the simulation or just go for higher volume and faster clock rate? Is there any setting which can also help increase the calculation efficiency (like letting GPU come into play)? Thank you so much!!

Answers

  • LitoLito Posts: 113Ansys Employee
    edited May 6

    @xyjxyj1992

    Lumerical does not support GPU acceleration. Best option is a multi-processor computer. These systems provide good performance because each processor has it's own memory bus connection to the RAM. Simulation speeds are typically limited by the memory bandwidth between RAM and processor, so having one memory bus per processor means the simulation speed tends to scale well with the number of processors. See this this post for more information. This post on our FDTD tests/benchmarks might come handy.

    Best,

    Lito

  • xyjxyj1992xyjxyj1992 Posts: 18Member

    Thank you so much for your reply! Do you mean more cores (or threads) the better or do you mean more than one CPU in a computer can help accelrate the simulation?

  • LitoLito Posts: 113Ansys Employee
    edited May 10

    @xyjxyj1992,

    From the article, I think the more memory channels supported by your CPU the better. e.g. an 8 core system with 8 memory channels will perform better than one with only 2 or 4 memory channels. Dual sockets/CPUs might offer better CPU-Memory bandwidth than a single CPU system.

  • xyjxyj1992xyjxyj1992 Posts: 18Member

    Hi Lito, I actually have another question regarding the benchmark scores on this website https://forum.ansys.com/discussion/25782/lumerical-fdtd-simulation-benchmarks. Is the results of M5.24x large 1130Mnodes/s with two CPUs running simltaneously or just with a single CPU?

  • LitoLito Posts: 113Ansys Employee

    @xyjxyj1992 ,

    As shown in the table, the instance has 2 Intel Xeon Platinum 8175 CPUs with a total of 96 threads/processes.

    The FDTD solver speed for the sample simulation using 96 threads is 1130 Mnodes/s


  • xyjxyj1992xyjxyj1992 Posts: 18Member

    I see, thanks for your reply, does that mean with single 8175 CPU, you can only reach 565Mnodes/s?

  • LitoLito Posts: 113Ansys Employee
    edited July 29

    @xyjxyj1992, I don't think that would be the case and the difference in performance is not linear in terms of the number of CPU/cores as seen on the results from the article. Will have to test on 1 CPU to get the FDTD solver speed for the same simulation file used in the article. Speed could vary depending on the simulation and machine.

  • xyjxyj1992xyjxyj1992 Posts: 18Member

    Thanks for your reply, I understand the last part. But what I really want to know here is that does 2 CPUs grant you twice of the speed or less compared to a single CPU under the same configration and the same simulation file? Thank you!

  • LitoLito Posts: 113Ansys Employee
    edited July 30

    Yes, 2 CPU/processor machines have better performance but not in a linear way vs the FDTD solver rate/speed. i.e. doubling the bandwidth does not mean that the FDTD solver rate will double. As seen in our example increasing the number of processes/threads used to run the simulation is not linear in terms of the FDTD solver rate. Running the simulation from 8 to 16 to 36 processes does not provide a linear performance increase.


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