主机并行运算问题

青山

组里刚弄了台主机，32核64线程的AMD EPYC 7502，ubuntu18.04上跑OF7，但是测试了一下，12核并行、24核并行和不并行的速度都是一样的，几十万网格和几万网格案例都试了，都是并行速度和没并行一样，这是什么原因？跑的时候我也看了系统监视器，的确并行的核的占用都起来了，风扇声音也贼大，但是速度一点没提升是哪里出了问题？

cccrrryyy

@青山并行的时候具体命令是什么，有没有加-parallel？另外机器开了超线程吗？

青山

@cccrrryyy mpirun -np 24 twoPhaseEulerFoam -parallel ，命令应该没问题，我在其他电脑上并行的话都挺快的，就这机子不行。没有超线程，32核64线程我只用了24个核。

cccrrryyy

@青山那这听起来是机子本身的问题了，硬件层面的了。按道理，一台机器内部也不涉及网络，跟网络也无关。

青山

@cccrrryyy 是的，跑起来的时候24个cup的占用都起来了，就是速度没块，我再研究研究，感谢！

李东岳

@青山 https://www.cfd-china.com/topic/3988/200万网格并行算力测试-openfoam版本跑一下我这个标准算例

星星星星晴

@青山原生ubuntu？

青山

@星星星星晴是的，原生的20.04

星星星星晴

@青山跑一下大佬的算力测试，看看怎么样，顺便把你这个case的log发一下开头的部分出来看看

青山

@星星星星晴没问题，明天算一下再回来反馈

青山

@李东岳大佬跑完了，这7502感觉有点拉胯啊

cccrrryyy

@青山不太熟悉AMD，7532和7502差别大么？感觉用的7532还不错的样子

青山

@cccrrryyy 我看东岳老师测试的，7502跑32核60多秒就跑完了，我比他慢了十倍不知道是硬件的问题还是设置的问题

星星星星晴

@青山发一下log文件啊。。你这个截图有什么用呢。。32核多少内存？内存怎么装的？

青山

@星星星星晴来了，大佬帮我看看，内存是16*8的


*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  7
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
Build  : 7-3bcbaf946ae9
Exec   : reactingTwoPhaseEulerFoam -parallel
Date   : Jan 18 2022
Time   : 13:20:12
Host   : "ps"
PID    : 6349
I/O    : uncollated
Case   : /home/ps/OpenFoam/zf/tube
nProcs : 24
Slaves : 
23
(
"ps.6350"
"ps.6351"
"ps.6352"
"ps.6353"
"ps.6354"
"ps.6355"
"ps.6356"
"ps.6357"
"ps.6358"
"ps.6359"
"ps.6360"
"ps.6361"
"ps.6362"
"ps.6363"
"ps.6364"
"ps.6365"
"ps.6366"
"ps.6367"
"ps.6368"
"ps.6369"
"ps.6370"
"ps.6371"
"ps.6372"
)

Pstream initialized with:
    floatTransfer      : 0
    nProcsSimpleSum    : 0
    commsType          : nonBlocking
    polling iterations : 0
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0


PIMPLE: No convergence criteria found


PIMPLE: No corrector convergence criteria found
        Calculations will do 3 corrections


PIMPLE: Operating solver in transient mode with 3 outer correctors

星星星星晴

@青山看起来没啥问题啊。。神奇了

星星星星晴

@青山 sudo dmidecode -t memory | grep Channel 看一下你的内存工作模式

青山

@星星星星晴这里有问题吗？

星星星星晴

@青山看不出来有什么问题，看其他大佬们的吧。。
实在不行重装，装ub1804，看起来都没啥问题。。

青山

@星星星星晴好的吧

李东岳

@青山前几步计算的log贴一下？

青山

@李东岳


------------*\
 =========                 |
 \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
  \\    /   O peration     | Website:  https://openfoam.org
   \\  /    A nd           | Version:  7
    \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
Build  : 7-3bcbaf946ae9
Exec   : reactingTwoPhaseEulerFoam -parallel
Date   : Jan 18 2022
Time   : 13:20:12
Host   : "ps"
PID    : 6349
I/O    : uncollated
Case   : /home/ps/OpenFoam/zf/tube
nProcs : 24
Slaves : 
23
(
"ps.6350"
"ps.6351"
"ps.6352"
"ps.6353"
"ps.6354"
"ps.6355"
"ps.6356"
"ps.6357"
"ps.6358"
"ps.6359"
"ps.6360"
"ps.6361"
"ps.6362"
"ps.6363"
"ps.6364"
"ps.6365"
"ps.6366"
"ps.6367"
"ps.6368"
"ps.6369"
"ps.6370"
"ps.6371"
"ps.6372"
)

Pstream initialized with:
   floatTransfer      : 0
   nProcsSimpleSum    : 0
   commsType          : nonBlocking
   polling iterations : 0
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0


PIMPLE: No convergence criteria found


PIMPLE: No corrector convergence criteria found
       Calculations will do 3 corrections


PIMPLE: Operating solver in transient mode with 3 outer correctors



Reading g

Reading hRef
Creating phaseSystem

Selecting twoPhaseSystem populationBalanceTwoPhaseSystem
Selecting phaseModel for air: purePhaseModel
Selecting diameterModel for phase air: velocityGroup
Selecting thermodynamics package 
{
   type            heRhoThermo;
   mixture         pureMixture;
   transport       const;
   thermo          eConst;
   equationOfState rhoConst;
   specie          specie;
   energy          sensibleInternalEnergy;
}

Calculating face flux field phi.air
Selecting turbulence model type RAS
Selecting RAS turbulence model mixtureKEpsilon
RAS
{
   RASModel        mixtureKEpsilon;
   turbulence      on;
   printCoeffs     on;
   Cmu             0.09;
   C1              1.44;
   C2              1.92;
   C3              1.92;
   Cp              0.25;
   sigmak          1;
   sigmaEps        1.3;
}

Selecting phaseModel for water: purePhaseModel
Selecting diameterModel for phase water: constant
Selecting thermodynamics package 
{
   type            heRhoThermo;
   mixture         pureMixture;
   transport       const;
   thermo          eConst;
   equationOfState rhoConst;
   specie          specie;
   energy          sensibleInternalEnergy;
}

Calculating face flux field phi.water
Selecting turbulence model type RAS
Selecting RAS turbulence model mixtureKEpsilon
RAS
{
   RASModel        mixtureKEpsilon;
   turbulence      on;
   printCoeffs     on;
   Cmu             0.09;
   C1              1.44;
   C2              1.92;
   C3              1.92;
   Cp              0.25;
   sigmak          1;
   sigmaEps        1.3;
}

No MRF models present

Selecting default blending method: linear
Selecting drag blending method: linear
Selecting surfaceTensionModel for (air and water): constant
Selecting aspectRatioModel for (air in water): constant
Selecting aspectRatioModel for (water in air): constant
Selecting dragModel for (air and water): segregated
Selecting swarmCorrection for (air and water): none
Selecting dragModel for (air in water): IshiiZuber
Selecting swarmCorrection for (air in water): Tomiyama
Selecting dragModel for (water in air): IshiiZuber
Selecting swarmCorrection for (water in air): Tomiyama
Selecting virtualMassModel for (air in water): constantCoefficient
Selecting virtualMassModel for (water in air): constantCoefficient
Selecting heatTransferModel for (air in water): RanzMarshall
Selecting heatTransferModel for (water in air): RanzMarshall
Calculating field g.h

Reading field p_rgh

Courant Number mean: 4.48994e-05 max: 0.00609375

Starting time loop

Courant Number mean: 4.48994e-05 max: 0.00609375
Max Ur Courant Number = 0
Time = 5e-05

PIMPLE: Iteration 1
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 8.97988e-05  Min(alpha1) = 0  Max(alpha1) = 0.25
Constructing momentum equations
GAMG:  Solving for p_rgh, Initial residual = 0.990339, Final residual = 7.12114e-09, No Iterations 43
PIMPLE: Iteration 2
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 8.97988e-05  Min(alpha1) = 0  Max(alpha1) = 0.25
Constructing momentum equations
GAMG:  Solving for p_rgh, Initial residual = 0.00172072, Final residual = 8.24851e-09, No Iterations 14
PIMPLE: Iteration 3
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 8.97988e-05  Min(alpha1) = 0  Max(alpha1) = 0.25
populationBalance bubbles: Iteration 1
DILUPBiCGStab:  Solving for f0.air.bubbles, Initial residual = 1, Final residual = 1.07449e-10, No Iterations 1
DILUPBiCGStab:  Solving for f1.air.bubbles, Initial residual = 1, Final residual = 1.0744e-10, No Iterations 1
DILUPBiCGStab:  Solving for f2.air.bubbles, Initial residual = 1, Final residual = 1.07565e-10, No Iterations 1
DILUPBiCGStab:  Solving for f3.air.bubbles, Initial residual = 1, Final residual = 1.07601e-10, No Iterations 1
DILUPBiCGStab:  Solving for f4.air.bubbles, Initial residual = 1, Final residual = 1.07472e-10, No Iterations 1
DILUPBiCGStab:  Solving for f5.air.bubbles, Initial residual = 1, Final residual = 1.07428e-10, No Iterations 1
DILUPBiCGStab:  Solving for f6.air.bubbles, Initial residual = 1, Final residual = 1.07231e-10, No Iterations 1
DILUPBiCGStab:  Solving for f7.air.bubbles, Initial residual = 1, Final residual = 1.07023e-10, No Iterations 1
DILUPBiCGStab:  Solving for f8.air.bubbles, Initial residual = 1, Final residual = 1.06289e-10, No Iterations 1
DILUPBiCGStab:  Solving for f9.air.bubbles, Initial residual = 1, Final residual = 1.04711e-10, No Iterations 1
DILUPBiCGStab:  Solving for f10.air.bubbles, Initial residual = 1, Final residual = 1.00915e-10, No Iterations 1
DILUPBiCGStab:  Solving for f11.air.bubbles, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab:  Solving for f12.air.bubbles, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab:  Solving for f13.air.bubbles, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab:  Solving for f14.air.bubbles, Initial residual = 0, Final residual = 0, No Iterations 0
air Sauter mean diameter, min, max = 4.65318e-05 4.65237e-05 4.65318e-05
air sizeGroups-sum volume fraction, min, max = 1 1 1
bubbles sizeGroup phase fraction first, last = 8.85697e-08 0
Constructing momentum equations
GAMG:  Solving for p_rgh, Initial residual = 0.000995987, Final residual = 6.44985e-09, No Iterations 11
smoothSolver:  Solving for epsilonm, Initial residual = 0.360485, Final residual = 5.98015e-08, No Iterations 6
smoothSolver:  Solving for km, Initial residual = 1, Final residual = 4.14411e-08, No Iterations 6
ExecutionTime = 0.14 s


Courant Number mean: 0.0537623 max: 1.16043
Max Ur Courant Number = 0.0897572
Time = 0.0001

PIMPLE: Iteration 1
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 0.000179598  Min(alpha1) = 0  Max(alpha1) = 0.25
Constructing momentum equations
GAMG:  Solving for p_rgh, Initial residual = 0.00793744, Final residual = 8.90127e-09, No Iterations 30
PIMPLE: Iteration 2
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 0.000179598  Min(alpha1) = 0  Max(alpha1) = 0.25
Constructing momentum equations
GAMG:  Solving for p_rgh, Initial residual = 0.0765251, Final residual = 7.71052e-09, No Iterations 16
PIMPLE: Iteration 3
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 0.000179598  Min(alpha1) = 0  Max(alpha1) = 0.25
populationBalance bubbles: Iteration 1
DILUPBiCGStab:  Solving for f0.air.bubbles, Initial residual = 0.147551, Final residual = 4.86871e-11, No Iterations 1
DILUPBiCGStab:  Solving for f1.air.bubbles, Initial residual = 0.0394195, Final residual = 1.02867e-11, No Iterations 1
DILUPBiCGStab:  Solving for f2.air.bubbles, Initial residual = 0.736843, Final residual = 2.25619e-10, No Iterations 1
DILUPBiCGStab:  Solving for f3.air.bubbles, Initial residual = 0.793873, Final residual = 2.42534e-10, No Iterations 1
DILUPBiCGStab:  Solving for f4.air.bubbles, Initial residual = 0.857026, Final residual = 2.6112e-10, No Iterations 1
DILUPBiCGStab:  Solving for f5.air.bubbles, Initial residual = 0.608674, Final residual = 1.86077e-10, No Iterations 1
DILUPBiCGStab:  Solving for f6.air.bubbles, Initial residual = 0.196465, Final residual = 5.34906e-11, No Iterations 1
DILUPBiCGStab:  Solving for f7.air.bubbles, Initial residual = 0.596202, Final residual = 1.77238e-10, No Iterations 1
DILUPBiCGStab:  Solving for f8.air.bubbles, Initial residual = 0.32325, Final residual = 9.33873e-11, No Iterations 1
DILUPBiCGStab:  Solving for f9.air.bubbles, Initial residual = 0.785256, Final residual = 1.98355e-10, No Iterations 1
DILUPBiCGStab:  Solving for f10.air.bubbles, Initial residual = 0.727823, Final residual = 1.4766e-10, No Iterations 1
DILUPBiCGStab:  Solving for f11.air.bubbles, Initial residual = 1, Final residual = 1.35917e-10, No Iterations 1
DILUPBiCGStab:  Solving for f12.air.bubbles, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab:  Solving for f13.air.bubbles, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab:  Solving for f14.air.bubbles, Initial residual = 0, Final residual = 0, No Iterations 0
air Sauter mean diameter, min, max = 4.6532e-05 4.65318e-05 4.65537e-05
air sizeGroups-sum volume fraction, min, max = 1 0.999972 1
bubbles sizeGroup phase fraction first, last = 1.77403e-07 0
Constructing momentum equations
GAMG:  Solving for p_rgh, Initial residual = 0.0649563, Final residual = 6.62621e-09, No Iterations 17
smoothSolver:  Solving for epsilonm, Initial residual = 0.24891, Final residual = 1.7812e-08, No Iterations 6
smoothSolver:  Solving for km, Initial residual = 0.212581, Final residual = 2.92726e-08, No Iterations 6
ExecutionTime = 0.27 s


Courant Number mean: 0.0538033 max: 1.18845
Max Ur Courant Number = 0.12208
Time = 0.00015

PIMPLE: Iteration 1
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 0.000269397  Min(alpha1) = 0  Max(alpha1) = 0.25
Constructing momentum equations
GAMG:  Solving for p_rgh, Initial residual = 0.148212, Final residual = 7.88969e-09, No Iterations 17
PIMPLE: Iteration 2
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 0.000269397  Min(alpha1) = 0  Max(alpha1) = 0.25
Constructing momentum equations
GAMG:  Solving for p_rgh, Initial residual = 0.0744514, Final residual = 5.55115e-09, No Iterations 18
PIMPLE: Iteration 3
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 0.000269397  Min(alpha1) = 0  Max(alpha1) = 0.25
populationBalance bubbles: Iteration 1
DILUPBiCGStab:  Solving for f0.air.bubbles, Initial residual = 0.0782433, Final residual = 4.79582e-11, No Iterations 1
DILUPBiCGStab:  Solving for f1.air.bubbles, Initial residual = 0.163708, Final residual = 8.79559e-11, No Iterations 1
DILUPBiCGStab:  Solving for f2.air.bubbles, Initial residual = 0.412078, Final residual = 2.36687e-10, No Iterations 1
DILUPBiCGStab:  Solving for f3.air.bubbles, Initial residual = 0.425663, Final residual = 2.43918e-10, No Iterations 1
DILUPBiCGStab:  Solving for f4.air.bubbles, Initial residual = 0.43729, Final residual = 2.49922e-10, No Iterations 1
DILUPBiCGStab:  Solving for f5.air.bubbles, Initial residual = 0.376317, Final residual = 2.14072e-10, No Iterations 1
DILUPBiCGStab:  Solving for f6.air.bubbles, Initial residual = 0.974911, Final residual = 5.33381e-10, No Iterations 1
DILUPBiCGStab:  Solving for f7.air.bubbles, Initial residual = 0.367985, Final residual = 1.98277e-10, No Iterations 1
DILUPBiCGStab:  Solving for f8.air.bubbles, Initial residual = 0.238507, Final residual = 1.18735e-10, No Iterations 1
DILUPBiCGStab:  Solving for f9.air.bubbles, Initial residual = 0.396462, Final residual = 1.61137e-10, No Iterations 1
DILUPBiCGStab:  Solving for f10.air.bubbles, Initial residual = 0.365836, Final residual = 1.05167e-10, No Iterations 1
DILUPBiCGStab:  Solving for f11.air.bubbles, Initial residual = 0.798764, Final residual = 1.27828e-10, No Iterations 1
DILUPBiCGStab:  Solving for f12.air.bubbles, Initial residual = 0.999974, Final residual = 7.83893e-11, No Iterations 1
DILUPBiCGStab:  Solving for f13.air.bubbles, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab:  Solving for f14.air.bubbles, Initial residual = 0, Final residual = 0, No Iterations 0
air Sauter mean diameter, min, max = 4.65323e-05 4.65318e-05 4.65886e-05
air sizeGroups-sum volume fraction, min, max = 0.999999 0.999917 1
bubbles sizeGroup phase fraction first, last = 2.66368e-07 0
Constructing momentum equations
GAMG:  Solving for p_rgh, Initial residual = 0.0789003, Final residual = 8.16298e-09, No Iterations 16
smoothSolver:  Solving for epsilonm, Initial residual = 0.217737, Final residual = 1.58357e-08, No Iterations 6
smoothSolver:  Solving for km, Initial residual = 0.191623, Final residual = 2.29973e-08, No Iterations 8
ExecutionTime = 0.38 s

李东岳

@青山我那个标准算例的log

青山

@李东岳


/*---------------------------------------------------------------------------*\
 =========                 |
 \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
  \\    /   O peration     | Website:  https://openfoam.org
   \\  /    A nd           | Version:  7
    \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
Build  : 7-3bcbaf946ae9
Exec   : pisoFoam -parallel
Date   : Jan 18 2022
Time   : 10:22:57
Host   : "ps"
PID    : 4116
I/O    : uncollated
Case   : /home/ps/OpenFoam/benchMark/core_16
nProcs : 16
Slaves : 
15
(
"ps.4117"
"ps.4118"
"ps.4119"
"ps.4120"
"ps.4121"
"ps.4122"
"ps.4123"
"ps.4124"
"ps.4125"
"ps.4126"
"ps.4127"
"ps.4128"
"ps.4129"
"ps.4130"
"ps.4131"
)

Pstream initialized with:
   floatTransfer      : 0
   nProcsSimpleSum    : 0
   commsType          : nonBlocking
   polling iterations : 0
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0

Reading field p

Reading field U

Reading/calculating face flux field phi

Selecting incompressible transport model Newtonian
Selecting turbulence model type laminar
Selecting laminar stress model Stokes
No MRF models present

Creating finite volume options from "constant/fvOptions"

Selecting finite volume options model type meanVelocityForce
   Source: momentumSource
   - selecting all cells
   - selected 2097152 cell(s) with volume 10
   Initial pressure gradient = 0


Starting time loop

fieldAverage fieldAverage1:
   Starting averaging at time 0

Time = 0.1

Courant Number mean: 0.731999 max: 1.22083
GAMG:  Solving for p, Initial residual = 0.629082, Final residual = 0.00572723, No Iterations 3
time step continuity errors : sum local = 1.06089e-05, global = -1.10517e-20, cumulative = -1.10517e-20
Pressure gradient source: uncorrected Ubar = 0.133489, pressure gradient = 0.000115089
GAMG:  Solving for p, Initial residual = 0.0561029, Final residual = 0.000467237, No Iterations 4
time step continuity errors : sum local = 1.28615e-06, global = -3.71636e-20, cumulative = -4.82152e-20
Pressure gradient source: uncorrected Ubar = 0.133489, pressure gradient = 0.000117874
GAMG:  Solving for p, Initial residual = 0.0152276, Final residual = 9.92056e-07, No Iterations 30
time step continuity errors : sum local = 2.62628e-09, global = -2.27344e-20, cumulative = -7.09497e-20
Pressure gradient source: uncorrected Ubar = 0.133489, pressure gradient = 0.000117425
ExecutionTime = 5.66 s  ClockTime = 6 s

Time = 0.2

Courant Number mean: 0.731698 max: 1.1641
GAMG:  Solving for p, Initial residual = 0.758295, Final residual = 0.00701504, No Iterations 3
time step continuity errors : sum local = 9.27309e-06, global = -2.6639e-13, cumulative = -2.66391e-13
Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000119203
GAMG:  Solving for p, Initial residual = 0.0736589, Final residual = 0.000696871, No Iterations 6
time step continuity errors : sum local = 6.00649e-07, global = -2.6639e-13, cumulative = -5.32781e-13
Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000117205
GAMG:  Solving for p, Initial residual = 0.0148478, Final residual = 9.08119e-07, No Iterations 43
time step continuity errors : sum local = 7.91859e-10, global = -2.66391e-13, cumulative = -7.99172e-13
Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.00011676
ExecutionTime = 11.78 s  ClockTime = 12 s

Time = 0.3

Courant Number mean: 0.731607 max: 1.18248
GAMG:  Solving for p, Initial residual = 0.476883, Final residual = 0.00315427, No Iterations 4
time step continuity errors : sum local = 2.37198e-06, global = -3.08998e-13, cumulative = -1.10817e-12
Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000119187
GAMG:  Solving for p, Initial residual = 0.0807666, Final residual = 0.000618685, No Iterations 5
time step continuity errors : sum local = 3.9245e-07, global = -3.08998e-13, cumulative = -1.41717e-12
Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000117229
GAMG:  Solving for p, Initial residual = 0.018049, Final residual = 8.80851e-07, No Iterations 45
time step continuity errors : sum local = 5.48708e-10, global = -3.08998e-13, cumulative = -1.72617e-12
Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.00011678
ExecutionTime = 18.04 s  ClockTime = 18 s

Time = 0.4

Courant Number mean: 0.731599 max: 1.17717
GAMG:  Solving for p, Initial residual = 0.1167, Final residual = 0.000969819, No Iterations 5
time step continuity errors : sum local = 6.01509e-07, global = -3.34128e-13, cumulative = -2.06029e-12
Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.00011923
GAMG:  Solving for p, Initial residual = 0.0809347, Final residual = 0.000631617, No Iterations 5
time step continuity errors : sum local = 3.90613e-07, global = -3.34128e-13, cumulative = -2.39442e-12
Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.00011725
GAMG:  Solving for p, Initial residual = 0.0184664, Final residual = 6.81898e-07, No Iterations 47
time step continuity errors : sum local = 4.15027e-10, global = -3.34128e-13, cumulative = -2.72855e-12
Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000116801
ExecutionTime = 24.52 s  ClockTime = 25 s

Time = 0.5

Courant Number mean: 0.731615 max: 1.19242
GAMG:  Solving for p, Initial residual = 0.108148, Final residual = 0.00095674, No Iterations 5
time step continuity errors : sum local = 5.80503e-07, global = -3.47575e-13, cumulative = -3.07612e-12
Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000119271
GAMG:  Solving for p, Initial residual = 0.0827827, Final residual = 0.000641763, No Iterations 5
time step continuity errors : sum local = 3.89751e-07, global = -3.47575e-13, cumulative = -3.4237e-12
Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000117272
GAMG:  Solving for p, Initial residual = 0.0189672, Final residual = 9.67464e-07, No Iterations 42
time step continuity errors : sum local = 5.75885e-10, global = -3.47575e-13, cumulative = -3.77127e-12
Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000116822
ExecutionTime = 30.63 s  ClockTime = 31 s

李东岳

从log上看没问题，不清楚为什么这么慢，之前他们别人也遇到过类似这种问题。所以买CFD服务器最好实测一下。

星星星星晴

@李东岳所以我之前问他们内存是怎么搞的，一般情况下，这玩意cpu肯定没问题，硬盘应该也不是瓶颈，内存是不是走的多通道模式是有可能是限制，但是看了一下，好像也是多通道的。原生Ubuntu，不是走虚拟机什么的，Case的log看起来也没什么问题。也不是多节点，都是本机的，也就没啥能慢的情况了啊。。而且这个应该不是自己弄的组装机吧？所以真心看不出来咋回事，重装一下系统看看好了～说不准神奇的解决了，或者试试老ubuntu ub18啊 ub16什么的

星星星星晴

@青山最简单粗暴的说，你们的内存条插满主板了么？或者说内存条有没有隔一个插一个，插了一半？没自己装过cluster，但是这玩意基本原理都是通用的。。支持8通道的话，8根插到对应的通道上就好。。他也是8根。完全看不出来为什么

cccrrryyy

@青山我记得mpi官网还是哪里可以找到非常简单的并行测试程序，类似于输出很多“Hello World”这种。你这个问题感觉不仅仅是openfoam的，可能任何一个并行的程序你调用都会出现无法并行的情况？

青山

@cccrrryyy 并行是没问题的，就是速度太慢，跟没并行差的不多

青山

@星星星星晴两个cpu槽插了一个cup，然后在cpu旁边的8个内存插槽都插了，搞不懂啥问题

李东岳

@青山之前有人从别人家买服务器发生过类似问题，但都在外地。如果在北京的话，可以让我学生看看你那个机器，我也好奇怎么回事。

青山

@李东岳感谢东岳老师，机子在杭州。超微的主板，买来都是配好的，一直没测试，最近测了几个案例才发现问题。标准算例里面8核的并行速度比16核还快我是真想不通

cccrrryyy

@青山同在杭州，看来杭州现在做CFD多起来了啊

李东岳

@青山你这个现在只能是重新做系统试一下。虽然我感觉基本不会有改变。感觉不是软件的问题。很奇怪怎么回事。

另外就是你们可以把机器发北京过来，现在学生都放假了，只能我在春节期间在硬件层面给你们debug一下。但是需要你们老师出一定的费用。如果要这么搞的话，可以邮件联系我。

青山

@李东岳感谢东岳老师，打算先找售后过来看看，如果他们说硬件没问题，换系统也没有改善的话，年后可能会麻烦东岳老师帮忙先提前向东岳老师和CFD中文网的朋友们问声新年好！

李东岳

@青山他们做服务器，你跑CFD算例跟他们说对比结果，估计他们彻底懵掉了，哈哈。

谢谢，新年好，剩下10天过年了