Re: [ESPResSo-users] Simulation of fluid using LB-method

[Ulf Schiller]

On 01/27/2014 11:54 AM, Wink, Markus wrote:
> 3) Even though, the velocity profile saturates, it takes pretty long
> (time scale of days). The saturation sets in at about 350 times the
> “integration 1000” command. This corresponds to a time scale of ms in Si
> units. Besides using OpenMpi or the GPU impementation, is there anyway
> to speeden up the simulation? For example by adjusting the parameter tau
> in the lbfluid command?

Hi,

that sounds a bit strange to me. If your system is 50^3 and you 
integrate 1000 steps, that gives 125*10^6 site updates. On a reasonably 
modern CPU, a reasonable LB code should get to around 10M SUPS (million 
site updates per second), that is, one call of "integrate 1000" should 
not take much more than 10 seconds, so 350 calls roughly one hour not 
days. Can you check how many site updates per second you get on your system?

Cheers,
Ulf

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