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-   -   Does it metter to increase RAM for solver speed?? (http://www.cfd-online.com/Forums/main/14862-does-metter-increase-ram-solver-speed.html)

raima February 28, 2008 07:18

Does it metter to increase RAM for solver speed??
 
Hi, I was initially running a solver on 4 GB linux m/c. My runtime was around 7.5 days. I increased RAM till 8 GB, but runtime has reduced only by half day. I need to ask, wher did I lack??? Does it metter to increase RAM for solver speed?? Is it also depending on mesh quality??? My mesh quality is gud.

regards raima.


TG February 28, 2008 11:47

Re: Does it metter to increase RAM for solver spee
 
If you have a 32bit OS or machine, then increasing the RAM beyond 4GB does nothing. If you have a 64bit OS and 64bit machine then you can increase the RAM beyond 4GB. If the problem takes more memory than available, then the machine will swap and run slow. Increasing the memory will speed up the machine until you have enough so that it no longer swaps. Once it stops swapping, increasing the memory further will have no effect. If you run the "top" command you ought to be able to see how much real memory is used vs how much virtual (ie swap space) and how much your job requires. Runtime also depends on mesh quality as "good" meshes tend to converge quicker than "bad" ones.


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