[ESPResSo-users] different outcomes for CPU and GPU

[Renáta Tóthová]

Hello, Espresso developers,

I am a member of the Cell-in-fluid research group in Slovakia and I have 
encountered this problem:
I have run the simulation in periodic channel with fluid only. There 
were only bottom and top wall and fluid flowed due to external force in 
x direction in the channel.
In first case, the fluid was computed using CPU - command lbfluid cpu. 
In second case, the fluid was computed using GPU - command lbfluid gpu. 
In both cases, there is Poiseuille/parabolic flow in the channel, but 
the values of velocity differ in the two outputs. The values are from a 
stable flow, after several thousand integration steps. The GPU 
calculations run on Nvidia Tesla machine. I have used current espresso 
master branch from github.

In the attachment, I am sending you the tcl script I have used.
Do you know what could be the issue?

Please, let me know. Thank you.
Have a nice day,

Renata Tothova

testCpuGpuFluid.tcl
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