[Gate-users] Parallel simulations and hardware specifications

[Alex Vergara Gil]

Dear Matthieu

You may want to read the thread "Adding G4MTRunManager support to
Gate", on it we explain our progress to make Gate running in
Multithread mode and you are also welcome to contribute to the git
repository in https://github.com/BishopWolf/Gate. Once we finally set
MT mode it can be integrated into official Gate repository to run, for
instance, in an Intel Xeon Phi card without further requirements.

Regards
Alex

2015-04-10 10:01 GMT-04:00, Matthieu Dondey <m.dondey at gmail.com>:
> ​​
>
> Dear Gaters,
>
>
>
> We expect to soon have some funds in our lab to buy a simulation
> workstation and one of its purposes will be Gate Monte Carlo simulations.
>
> I’ve tried to gather what the important hardware specifications are but I’d
> like to have advice from people who are already performing parallel
> simulations on multi-thread workstation or clusters.
>
> My first question is about methodology:
>
> To split a simulation into several jobs when using a multi-core computer,
> is the process the same as the one described in the Users guide - Parallel
> Computing -> How to use Gate on a cluster?
>
> Next, is it really beneficial to use GPU + CPU instead of CPUs alone? Is
> the Nvidia CUDA technology well adapted to Gate simulations and what are
> its benefits and downsides?
>
> Lastly, I’ve read in the Users Guide:
>
> *In planning simulation time, it is important to be aware that Gate
> simulations currently seem to benefit only from the addition of physical
> CPUs. A computer with 8 hyper-threaded physical CPU cores (16 logical CPUs)
> will have the same computational efficiency if 8 processes are run
> simultaneously as it would with 16 simultaneous processes.*
>
>
>
> Can someone confirm and explain why it is impossible to use logical threads
> with Gate (“seem to benefit” doesn’t seem realy categorical)? Is it an
> issue which will be fixed in next versions of GATE? Is it a Geant4 specific
> problem? Or is it possible to exploit logical threads on Geant4?
>
>
> Any help will be greatly appreciated and I'd be very grateful about any
> other advice on hardware specifications (RAM usage, important spec of
> processors, benefit of a SSD, etc.)
>
>
> Cheers,
>
>
> Matthieu
>