|Message: Calculation speed in GEANT4||Not Logged In (login)|
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I didn't find any *really* appropriate group for this message, but as I saw another similar message in this group (http://geant4-hn.slac.stanford.edu:5090/HyperNews/public/get/docsexamples/12.html), I'm posting it here.
I'm just trying to learn GEANT4, and was quite impressed by the capabilities of this package, but soon my enthusiasm turn into a disappointment. I compared the calculation speed of GEANT4 and GEANT3 on a couple of examples. Namely, I just run the example N01 with /event/verbose 0 and /tracking/verbose 0 and with 20000 events. It takes about 40 seconds on my PC, so 500 events/sec. For comparison I just took my old GEANT3 program simulating gamma response of a Germanium detector, with a similar level of complexity of the geometry. It makes about 10000 events/sec, a factor of 20 faster. I also made a GEANT4 program which has exactly the same geometry as the GEANT3 code, and also does basically the same. It makes 70 events/sec, another order of magnitude down. Example N03 with exampleN03.large_N.in as input makes about 5 events/second on my PC.
I would like to ask the experts for the reason of such tremendous decrease of calculation speed. Is there any way for optimization/improvement? I would still accept a factor of 2-3 loss of speed for the sake of whatever other advantages which GEANT4 probably gives, but with more than 2 orders of magnitude I will definitely stay with the old GEANT3.
Best regards, Yuri
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