Ram memory doubt

L3munoz · December 9, 2009, 08:51

Hi everybody!

I've been checking different threads on the forum but i dont know exactly for my case...It seems there is a thumb rule which says that u need about 1Gb for every 1 million cells...IN my case i'm gonna work with a 6 millions cells case and my desktop has 8 gb ram. However i couldnt run with it. I've installed windows 64 bits but fluent is 32 bits one...

Any advice? should i get more ram memory? or shall i work with a 64 bits fluent version?

Allan Walsh · December 9, 2009, 13:21

Isn't one of the advantages of Windows 64 that it can access more than 2 Gig of RAM? Seems to be limit in 32 bit version, unless you are running a parallel version of Fluent.

ski · December 9, 2009, 14:30

A 32 bit program can only address 4GB of ram in theory and in reality, only about 3.4GB for reasons that I'm not 100% sure of. (I think is something to do with the system needing the rest)

If your running a 64bit OS your 64bit programs can access much more memory however any 32bit progs will be run via an emulator (WoW64) so will not have this benefit.

You will need a 64bit version of Fluent, or will need to run your job across several workstations in parallel.

L3munoz · December 9, 2009, 14:34

Hi ski!

thanks for ur answer. Now i can understand also Allan's one (thanks Allan also for urs...) But is there any way to run a case in parallel in my computer. whenever i've done it was in a cluster, but in my case, although is true that there are 4 units of 2 gigas, i've never tried to run it in parallel...is therefore possible?

December 9, 2009, 08:51	Ram memory doubt	#1
L3munoz Member Jorge Muñoz Join Date: Apr 2009 Posts: 56 Rep Power: 17	Hi everybody! I've been checking different threads on the forum but i dont know exactly for my case...It seems there is a thumb rule which says that u need about 1Gb for every 1 million cells...IN my case i'm gonna work with a 6 millions cells case and my desktop has 8 gb ram. However i couldnt run with it. I've installed windows 64 bits but fluent is 32 bits one... Any advice? should i get more ram memory? or shall i work with a 64 bits fluent version?

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December 9, 2009, 13:21		#2
Allan Walsh Member Allan Walsh Join Date: Mar 2009 Posts: 56 Rep Power: 17	Isn't one of the advantages of Windows 64 that it can access more than 2 Gig of RAM? Seems to be limit in 32 bit version, unless you are running a parallel version of Fluent.

December 9, 2009, 14:30		#3
ski New Member AS Join Date: Jul 2009 Posts: 16 Rep Power: 17	A 32 bit program can only address 4GB of ram in theory and in reality, only about 3.4GB for reasons that I'm not 100% sure of. (I think is something to do with the system needing the rest) If your running a 64bit OS your 64bit programs can access much more memory however any 32bit progs will be run via an emulator (WoW64) so will not have this benefit. You will need a 64bit version of Fluent, or will need to run your job across several workstations in parallel.

December 9, 2009, 14:34		#4
L3munoz Member Jorge Muñoz Join Date: Apr 2009 Posts: 56 Rep Power: 17	Hi ski! thanks for ur answer. Now i can understand also Allan's one (thanks Allan also for urs...) But is there any way to run a case in parallel in my computer. whenever i've done it was in a cluster, but in my case, although is true that there are 4 units of 2 gigas, i've never tried to run it in parallel...is therefore possible?