|
[Sponsors] |
parallel processing problem with multiproc machine |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
January 28, 2006, 15:51 |
parallel processing problem with multiproc machine
|
#1 |
Guest
Posts: n/a
|
Hi everybody! I have a case which I solve with coupled implicit solver, about 500,000 cells. I tried to solve on 1 processor first to see how fast it does 1 iteration, and then tried with 8 processors. Surprisingly it was not faster. So my question is how does one efficiently distribute the job between 8 processors?
Thanks a lot. |
|
January 28, 2006, 17:15 |
Re: parallel processing problem with multiproc mac
|
#2 |
Guest
Posts: n/a
|
First thing to look at is the speed and latency of the interconnect, if it is a distributed system. Also, splitting 500 000 cells 8 ways is a bit too much. Try it with 2, 4 and 6 to see if that helps.
|
|
January 28, 2006, 19:11 |
Re: parallel processing problem with multiproc mac
|
#3 |
Guest
Posts: n/a
|
Coupled implicit solver requires heavy communication between CPU's (segregated and coupled explicit solvers don't). So it is efficient only when used on shared memory machines, where all processors have acess to all the memory in the same time. When used in a distributed memory environnement (supercomputer or cluster), its peformance degrades very quickly especially on small grids.In my experience, you will have to partition the grid with at least 200.000 elements per partition, so on this case you will have to use 2, max. 3 CPU's !!
Or you could switch to explicit solver, if you really have to solve using coupled solver. Razvan |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Parallel processing problem with Fluent | Harish | FLUENT | 3 | February 8, 2011 09:49 |
Problems with MFIX code and Parallel Processing. | Fernando Pio | Main CFD Forum | 4 | August 29, 2006 14:33 |
About parallel processing in Linux | tuks | CFX | 10 | August 8, 2005 08:22 |
parallel mode - small problem? | co2 | FLUENT | 2 | June 1, 2004 23:47 |
PC vs. Workstation | Tim Franke | Main CFD Forum | 5 | September 29, 1999 15:01 |