[已解决]单机多核并行的计算问题，到底哪里设置不对呢

离线phasearray

UID ：49164

注册：2009-12-18
登录：2013-04-29
发帖：23
等级：仿真新人

70楼发表于: 2012-03-06 02:16:29

三楼的回复是这样的！哈哈！

从图档看来.我的判定是授权问题与核数的问题，还有你解什么架构？感觉您目前MLFMM的不是很好到80点才通过。

1. Parallel Processing
* 32-bit systems can only address 2 GBytes of RAM per process
* 64-bit systems can address more than 2 GBytes of RAM per process and therefore have an advantage over 32-bit systems
* Scalable to multiple processor servers or clusters with various interconnect technologies (eg Ethernet, Myrinet, Infiniband)

2.就算是您在64-bit systems上安装了64-bit FEKO，授权是哪一种版本就是哪一种版本。

3. 32-bit单机版本就是2 GBytes；32-bit平行版本就每台2 GBytes，看您买了几个授权而定。 64-bit依法类推。

4.一个计算的8-10万网格，采用MLFMM
Technical Foundation

The MoM treats each of the N basis functions in isolation, thus resulting in an N2 scaling of memory requirements (to store the impedance matrix) and N3 in CPU-time (to solve the linear set of equations). It is thus clear that processing requirements for MoM solutions scale rapidly with increasing problem size. The MLFMM formulation's more efficient treatment of the same problem results in N.log(N) scaling in memory and N.log(N).log(N) in CPU time. In real applications this reduction in solution requirements can range to orders of magnitude.
Significant effort has also been invested in improving the parallel MLFMM formulation to achieve exceptionally high efficiency when distributing a simulation over multiple processors.
Asymptotic Memory Estimates for Different Applications
Application and Frequency Number of Unknowns Memory allocated
MoM MLFMM
Military aircraft at 690 MHz,
Ship (115m x 14 m) at 107 MHz,
Reflector antenna with aperture size 19 lambda 100 000 150 GByte 1 GByte
Military aircraft at 1.37 GHz,
Ship (115m x 14 m) at 214 MHz,
Reflector antenna with aperture size 38 lambda 400 000 2.4 TByte 4.5 GByte
Military aircraft at 2.65 GHz,
Ship (115m x 14 m) at 414 MHz,
Reflector antenna with aperture size 73 lambda 1 500 000 33.5 TByte 18 GByte

5.计算途中提示内存不足，不管是2核并行，还是3核、4核并行，均出现此类情况。而在最吃内存的preconditioner环节也没有需要很多内存，最多才4-5G?
5-1.授权问题
5-2. preconditioner这里你要准备实际比他多一倍的记忆体来做。
5-3.目前初步判定内存问题导致您无法求解，我建议您先使用1核先做求解试试看,再稍微调一下网格。