200万网格并行算力测试（OpenFOAM版本）
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@kennyadapter 你这个看起来就是带宽跟不上了
@来瓶热阔落 你看下你8核和4核的最开始时间步的log？类似这种，分别贴一下：Time = 0.1 Courant Number mean: 0.733413 max: 1.27933 GAMG: Solving for p, Initial residual = 0.0999699, Final residual = 0.000818608, No Iterations 6 time step continuity errors : sum local = 4.79761e-07, global = 8.13808e-20, cumulative = 1.63519e-17 Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.00012387 GAMG: Solving for p, Initial residual = 0.081007, Final residual = 0.000576888, No Iterations 6 time step continuity errors : sum local = 3.41793e-07, global = 5.45899e-20, cumulative = 1.64065e-17 Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000120508 GAMG: Solving for p, Initial residual = 0.0189675, Final residual = 9.02577e-07, No Iterations 39 time step continuity errors : sum local = 5.28191e-10, global = 1.77208e-20, cumulative = 1.64242e-17 Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.00011971 ExecutionTime = 173.99 s ClockTime = 174 s -
@东岳 在 200万网格管道流qDNS并行算力测试 中说：
东岳老师，那怎么调整带宽呢？有什么方法，或者需要更换什么配件吗？
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Time = 0.1 Courant Number mean: 0.731999 max: 1.22083 GAMG: Solving for p, Initial residual = 0.629705, Final residual = 0.00421935, No Iterations 3 time step continuity errors : sum local = 7.82336e-06, global = -1.9955e-20, cumulative = -1.9955e-20 Pressure gradient source: uncorrected Ubar = 0.13349, pressure gradient = 0.000114208 GAMG: Solving for p, Initial residual = 0.0563421, Final residual = 0.000354153, No Iterations 4 time step continuity errors : sum local = 9.75747e-07, global = 2.11991e-20, cumulative = 1.24408e-21 Pressure gradient source: uncorrected Ubar = 0.133489, pressure gradient = 0.000117378 GAMG: Solving for p, Initial residual = 0.0152771, Final residual = 8.66768e-07, No Iterations 18 time step continuity errors : sum local = 2.28999e-09, global = -1.80834e-20, cumulative = -1.68393e-20 Pressure gradient source: uncorrected Ubar = 0.133489, pressure gradient = 0.00011696 ExecutionTime = 4.61 s ClockTime = 5 s Time = 0.2 Courant Number mean: 0.731698 max: 1.1641 GAMG: Solving for p, Initial residual = 0.75843, Final residual = 0.00508023, No Iterations 3 time step continuity errors : sum local = 6.71701e-06, global = 1.79247e-12, cumulative = 1.79247e-12 Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000119141 GAMG: Solving for p, Initial residual = 0.0716405, Final residual = 0.000689194, No Iterations 5 time step continuity errors : sum local = 5.93336e-07, global = 1.79247e-12, cumulative = 3.58494e-12 Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000117204 GAMG: Solving for p, Initial residual = 0.014621, Final residual = 9.75203e-07, No Iterations 25 time step continuity errors : sum local = 8.46786e-10, global = 1.79247e-12, cumulative = 5.37741e-12 Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000116758 ExecutionTime = 9.1 s ClockTime = 9 s上面是4核，下面8核
Time = 0.1 Courant Number mean: 0.731999 max: 1.22083 GAMG: Solving for p, Initial residual = 0.629703, Final residual = 0.00603973, No Iterations 3 time step continuity errors : sum local = 1.11982e-05, global = 8.06587e-21, cumulative = 8.06587e-21 Pressure gradient source: uncorrected Ubar = 0.13349, pressure gradient = 0.000114193 GAMG: Solving for p, Initial residual = 0.0566187, Final residual = 0.00046644, No Iterations 4 time step continuity errors : sum local = 1.28491e-06, global = -2.9891e-20, cumulative = -2.18251e-20 Pressure gradient source: uncorrected Ubar = 0.133489, pressure gradient = 0.000117396 GAMG: Solving for p, Initial residual = 0.0153571, Final residual = 7.70794e-07, No Iterations 20 time step continuity errors : sum local = 2.0346e-09, global = -1.94705e-20, cumulative = -4.12956e-20 Pressure gradient source: uncorrected Ubar = 0.133489, pressure gradient = 0.000116978 ExecutionTime = 5.64 s ClockTime = 6 s Time = 0.2 Courant Number mean: 0.731698 max: 1.16413 GAMG: Solving for p, Initial residual = 0.75841, Final residual = 0.00736995, No Iterations 3 time step continuity errors : sum local = 9.74458e-06, global = 8.78067e-13, cumulative = 8.78067e-13 Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000119176 GAMG: Solving for p, Initial residual = 0.073429, Final residual = 0.000652992, No Iterations 6 time step continuity errors : sum local = 5.62596e-07, global = 8.78067e-13, cumulative = 1.75613e-12 Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000117203 GAMG: Solving for p, Initial residual = 0.0147366, Final residual = 9.38466e-07, No Iterations 23 time step continuity errors : sum local = 8.14733e-10, global = 8.78067e-13, cumulative = 2.6342e-12 Pressure gradient source: uncorrected Ubar = 0.1335, pressure gradient = 0.000116759 ExecutionTime = 11.02 s ClockTime = 11 s -
CPU: AMD Opteron(tm) Processor 6376 OS: debian 10 OpenFOAM: 8 # cores Wall time (s): ------------------------ 64 164.29 32 180.06 16 305.33 8 407.37 4 800.44 2 1981.19 1 3383.18CPU: Intel(R) Xeon(R) Platinum 8175M OS: ubuntu 18.04 OpenFOAM: 8 # cores Wall time (s): ------------------------ 48 77.08 24 99.2 12 123.14 6 234.82 3 366.02 1 1149.63CPU: Intel(R) Xeon(R) E5-2683 OS: ubuntu 14.04 OpenFOAM: 8 # cores Wall time (s): ------------------------ 28 224.8 14 214.99 8 246.61 4 383.36 2 721.88 1 1361滚来滚去……~(～o￣▽￣)～o 滚来滚去都不能让大家看出来我不是老师么 O_o
异步沟通方式(《posting style》from wiki)（下载后打开）：
https://www.jianguoyun.com/p/Dc52X2sQsLv2BRiqnKYD
提问的智慧(github在gitee的镜像)：
https://gitee.com/bestucan/How-To-Ask-Questions-The-Smart-Way -
滚来滚去……~(～o￣▽￣)～o 滚来滚去都不能让大家看出来我不是老师么 O_o
异步沟通方式(《posting style》from wiki)（下载后打开）：
https://www.jianguoyun.com/p/Dc52X2sQsLv2BRiqnKYD
提问的智慧(github在gitee的镜像)：
https://gitee.com/bestucan/How-To-Ask-Questions-The-Smart-Way -
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心血来潮测一下服务器 为什么会有这样的error 提示？ of41能做么
Reading/calculating face flux field phi Selecting incompressible transport model Newtonian Selecting turbulence model type laminar No MRF models present Creating finite volume options from "constant/fvOptions" Selecting finite volume options model type meanVelocityForce [0] [0] [0] --> FOAM FATAL IO ERROR: [0] keyword meanVelocityForceCoeffs is undefined in dictionary "/home/local.njord/maosui/benchMark/core_8/constant/fvOptions.momentumSource" [0] [0] file: /home/local.njord/maosui/benchMark/core_8/constant/fvOptions.momentumSource from line 20 to line 25. [0] [0] From function const Foam::dictionary& Foam::dictionary::subDict(const Foam::word&) const [0] in file db/dictionary/dictionary.C at line 642. [0] [2] [2] [2] --> FOAM FATAL IO ERROR: [2] keyword meanVelocityForceCoeffs is undefined in dictionary "IOstream.momentumSource" [2] -
中午在服务器上测试了一下这个算例，发现算例受核间通信的影响确实很大，在核心数较高时计算时长的收益很小甚至负收益==
以及8164是老cpu了吧，单核计算能力捉急。。CPU型号： Intel(R) Xeon(R) Platinum 8164 CPU @ 2GHz （8） 系统： Ubuntu 18.04.5 LTS 内存： 791160068 kB OpenFOAM版本：OpenFOAM-6 192 149.49 128 51.77 64 48.97 32 64.36 16 111.44 8 153.07 4 338.46 2 611.9 1 1249.7```逢山开路，遇水架桥
对流换热强化
