CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

dual processing

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   November 22, 2004, 08:52
Default dual processing
  #1
stk
Guest
 
Posts: n/a
could anyone inform me about the effectiveness of a system with 2 processors (pentium 4 for example) on windows platform? is the cpu power getting doubled? thanks

  Reply With Quote

Old   November 22, 2004, 09:59
Default Re: dual processing
  #2
Ralf Schmidt
Guest
 
Posts: n/a
I dont know about cpu power. But I can tell you, that Fluent might have problems with parallel processing.

We are using Workstations with 2 processors, and some thing doesnt work. For excample importing a mesh from gambit with two fluid zones (one fluid, the other one porous) is not possible. This just works with a normal PC. Also Floating point error might occur, referr to: http://www.cfd-online.com/Forum/fluent.cgi?read=23038

Ralf
  Reply With Quote

Old   November 22, 2004, 13:23
Default Re: dual processing
  #3
Evan Rosenbaum
Guest
 
Posts: n/a
We have dome some dual-processor runs in the past (v5.5). Fome some problems the increase in throughput was actually more than doubled. We think this is because FLUENT is optimized for parallel processing and required less iterations. Other runs were say 1.6-1.8 times faster.

Some things can't be run parallel (DTRM radiation for example).
  Reply With Quote

Old   November 22, 2004, 13:24
Default Re: dual processing
  #4
MML
Guest
 
Posts: n/a
I am using Fluent parrallel on Windows XP, with single P4 processor and Hyper Threading enabled.This results in software seeing two processors.

This has resulted in significant savings of time, each alternate iteration is done on different processor so solving time is reduced.

regards MML
  Reply With Quote

Old   November 22, 2004, 20:24
Default Re: dual processing
  #5
zxaar
Guest
 
Posts: n/a
i agree with ralf, that fluent has this problem if you have two zones, but after a lot of effort and you are lucky it can read this multizonal mesh also, in my case i had to make mesh around 10 times, with lot of tricks (i mean defining them as say solid rather than fluid zone , or interface to wall etc),
  Reply With Quote

Old   December 2, 2004, 15:23
Default Re: dual processing
  #6
Bill
Guest
 
Posts: n/a
This is a common problem that we (cd-adapco) see sometimes from customers who have switched over to StarCD from Fluent. The new solver from from CD Star-CCM+ has been specifically written from the ground up to take advantage of parallel processing. An old code, (like Fluent) has tried to add parallel processing after the fact. It only works for certain cases and not all models and I think that this is what you are running into

-Bill
  Reply With Quote

Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Superlinear speedup in OpenFOAM 13 msrinath80 OpenFOAM Running, Solving & CFD 18 March 3, 2015 06:36
NO model vs post processing in coal combustion,CFX sakalido CFX 1 April 15, 2011 15:07
recover solution from dual grid jamesproctor Main CFD Forum 0 July 30, 2010 16:31
How many CFX licenses for dual core processors? km CFX 12 September 8, 2006 16:18
Post Processing in FEM Abhijit Tilak Main CFD Forum 0 April 26, 2004 12:59


All times are GMT -4. The time now is 07:41.