[Gate-users] How to use multithread on Gate 7.2

[David Boersma]

Hi Mery MB,

We would love to run GATE in multithreaded mode, but for the time being 
that is not yet working. We think we may have to wait until Geant5 (no 
typo: Geant version five) is released. That will not happen any time 
soon. Also GATE internally needs a lot of work to be "thread-safe".

So in order to make full use of your multicore system, I would advise to 
treat it as a "cluster". You can install your favorite job submission 
system (I am using HTCondor, which is very easy to install on Ubuntu) 
and then just split up your simulation into many jobs that can be run in 
parallel. Make sure that you never exceed the available RAM (by being 
careful with your GATE macro, configuring your job management system to 
not allow more jobs when the RAM is almost completely used, or by 
throwing more money at it and installing more RAM, or etc). Also be 
careful with hyperthreading. On my own "number cruncher", the "htop" 
program reports 16 cores, but physically it has actually only 8 cores. I 
noticed that hyperthreading slows down GATE, even if there is enough 
RAM. So on my system I configure HTCondor to *not* use hyperthreading, 
running 8 jobs in parallel gives a slightly higher throughput than 
running 16 jobs in parallel: with 16, each individual job runs a bit 
more that 2x slower than with 8. YMMV.

There are several tools and scripts/programs floating around to assist 
you running GATE on clusters. AFAIK, all these tools (including "gjs" 
that is included in the GATE source tree) are tailored for specific use 
cases. If you tell us about your own intended use case then maybe some 
other mailing list members with similar use cases can advertise their 
favorite cluster tool to you.

(BTW: if anyone with some real concurrent programming experience happens 
to read this message, please feel free to have a look at our code, and 
share your thoughts and ideas about the way forward to MT-GATE  on the 
gate-devel mailing list.)

Good luck,
David Boersma


Den 25/06/2017 kl. 11:26, skrev Mery MB:
> Dear All Gate Developer and User
> 
> I want to run my Gate program on a 24 core PC. How can I use all core 
> for one program in Gate?
> 
> How we can use the Multi threaded option in Gate Programs?
> we should add some sentences to the program?
> 
> I will thank you if some one can help me in this issue.
> 
> Best Regards
> 
> 
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