Insufficient virtual memory
 

Dear Sir,

We have just installed an additional of 2GB Ram, that is now we have a total of 4GB Ram, for a computer in order to speed up the CFD modelling time and enlarge the capacity of the model. The number of grids is about 1.8 millions and the domain size is about 2250*2000*600. However, a message "Insufficient virtual memory" always appears and told us to increase the number of EARTH in cham.ini. We followed the step and when we increase the number up to 210000000, and start the model again, a nimmediately error message "insufficient virtual memory" comes out. It seems that we have reached the limit. As such, could you advise us how to fix this problem?

How can we increase the memory as we have sufficient physical Ram? How can we increase the size of F-array except using cham.ini? Why there is a limit for EARTH in cham.ini? Can this problem be solved?

Sammi

Re: Insufficient virtual memory
 

If you are running on WindowsXP, you may need to use the /3GB boot parameter. This is described in Cham's FAQ document, http://www.cham.co.uk/documentation/tr010.pdf , question 4 on page 3.

Searching Microsoft's website will provide instructions on how to activate the /3GB parameter.

My understanding is that, by default, Windows reserves address space between 2 - 4 GB for Windows, leaving the space between 0 - 2GB for programs. The /3GB switch moves windows up to 3 - 4GB, leaving 0-3GB addresses for programs.

Also, a "domain size of 2250*2000*600" would imply a model with 2.7 billion cells?

Re: Insufficient virtual memory
 

==>a "domain size of 2250*2000*600" would imply a model with 2.7 billion cells?

We are not using cell size of 1*1*1, we divided the whole domain into three sub-domains, and each sub-domain has different cell size, some coarser and some finer, which finally gives us the total number of cells of about 1.8 millions. Unfortunately, even this cannot be ran. I will try the above method, thank you very much!

Re: Insufficient virtual memory
 

I have not tried it, but you may be able to run PHOENICS under WinXP 64... it can address up to several terabytes of memory, and any RAM you don't have can be replaced by the swapfile. The WinXP-32 swapfile is 4GB max, the WinXP-64 swapfile I am using (not for PHOENICS) is currently 20GB with no problems. The 32-bit PHOENICS code can run under 64-bit Windows, but you need to talk to CHAM about getting a proper driver for your dongle (if you're using one) because the driver won't load under 64-bit OS's.

You indeed may run under XP 64-bits. The problem may be getting a driver for whatever license file or dongle you may have, but it is do-able.
Patti