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[ESPResSo-users] LBM fluid velocity difference GPU/CPU
From: |
Markus Gusenbauer |
Subject: |
[ESPResSo-users] LBM fluid velocity difference GPU/CPU |
Date: |
Mon, 01 Jul 2013 16:23:01 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130329 Thunderbird/17.0.5 |
Hi all,
I have a simple simulation with 1 particle in a channel and lbfluid. I
put a certain velocity at one side of the channel. Resulting particle
velocities differ a lot if I use GPU or CPU. In fact, 10 times the
velocity of CPU fluid equals approximately the velocity of the GPU (I
just compare particle position). I am using the latest master release
from github.
Here is the example script:
setmd time_step 0.1
setmd skin 0.2
thermostat off
setmd box_l 40 40 100
lbfluid gpu grid 1 dens 1.0 visc 1.5 tau 0.1 friction 0.5
lbboundary wall normal 1 0 0 dist 0.5 type 501
lbboundary wall normal -1 0 0 dist -39.5 type 501
lbboundary wall normal 0 1 0 dist 0.5 type 501
lbboundary wall normal 0 -1 0 dist -39.5 type 501
part 0 pos 20 20 20 type 0 mol 0 mass 1.5
set i 0
while { $i < 100 } {
puts "$i / 100, particle position [part 0 print pos]\r"
for { set iii 0 } { $iii < 40} { incr iii } {
for { set jjj 0 } { $jjj < 40 } { incr jjj } {
for { set kkk 0 } { $kkk < 1 } { incr kkk } {
lbnode $iii $jjj $kkk set u 0.0 0.0 0.1
}
}
}
integrate 1
incr i
}
I am not sure if the factor 10 is important or just a lucky coincidence.
Markus
- [ESPResSo-users] Problem MPI+GPU using LBM, Markus Gusenbauer, 2013/07/01
- Re: [ESPResSo-users] Problem MPI+GPU using LBM, Axel Arnold, 2013/07/01
- Re: [ESPResSo-users] Problem MPI+GPU using LBM, Axel Arnold, 2013/07/01
- Re: [ESPResSo-users] Problem MPI+GPU using LBM, Markus Gusenbauer, 2013/07/01
- Re: [ESPResSo-users] Problem MPI+GPU using LBM, Axel Arnold, 2013/07/01
- Re: [ESPResSo-users] Problem MPI+GPU using LBM, Markus Gusenbauer, 2013/07/01
- [ESPResSo-users] LBM fluid velocity difference GPU/CPU,
Markus Gusenbauer <=
- Re: [ESPResSo-users] LBM fluid velocity difference GPU/CPU, Owen Hickey, 2013/07/01