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

Increasing RAM decreases CPU time!!!

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 1, 2004, 14:57
Default Increasing RAM decreases CPU time!!!
  #1
Melih GULEREN
Guest
 
Posts: n/a
Hi everybody,

I had an interesting experience about the "RAM problem" in FLUENT. I ran the same job with two different computers. First: P4 2.8 Ghz with 2GB Ram, second: P4 3.0 Ghz with 1GB Ram. My job was using exactly the same RAM capacity (500 KB) for each computer. But, when I compared the CPU time for each, I saw that the performance of the second computer (although it has a faster CPU than first) was about 40 per cent less than the first one. Then, I concluded that increasing RAM in a computer must decrease the CPU time. So can it be right: More physical free memory you get in your computer, in much shorter times the jobs can be converged? What do you think?

PS: Operation systems were the same for the computers.

Best Regards...
  Reply With Quote

Old   April 2, 2004, 15:57
Default Re: Increasing RAM decreases CPU time!!!
  #2
Allan Walsh
Guest
 
Posts: n/a
I think that RAM is not RAM. That is, there are many different types of RAM, operating at different speeds. Any idea what you have in your different systems?

Or perhaps it is not that simple and % of CPU usage was not the same for both cases - say if other background applications grab some clock cycles.
  Reply With Quote

Old   April 5, 2004, 07:21
Default Re: Increasing RAM decreases CPU time!!!
  #3
gg
Guest
 
Posts: n/a
Did you check hyperthreading on second computer?
  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
TimeVaryingMappedFixedValue irishdave OpenFOAM Running, Solving & CFD 32 June 16, 2021 07:55
OpenFOAM 13 Intel quadcore parallel results msrinath80 OpenFOAM Running, Solving & CFD 13 February 5, 2008 06:26
Convergence moving mesh lr103476 OpenFOAM Running, Solving & CFD 30 November 19, 2007 15:09
The method of Checking the CPU time JunYoung Park Main CFD Forum 2 April 19, 1999 16:34
On the reduction of cpu time lee Main CFD Forum 4 March 7, 1999 23:02


All times are GMT -4. The time now is 11:02.